The reason for that fact, and the proof of it, is simple and clear: There was never only a written Torah. There were always two; a written Torah and an oral Torah, each dependent upon and coexisting with the other.
(The following is from The Jewish Virtual Library, one of the few really reliable sources online for information on Jewish history and teachings. Some emphases have been added in boldface)
There is much more at the site concerning the attitudes and approaches of the other two major movements in Judaism, Reform and Conservative; but the above is an excellent explanation of the Orthodox approach, which should put an end to discussions about the "literal" or "verbatim" reading of the Torah, unassisted by any "interpretation." Such a thing is clearly rendered impossible by the nature of the text itself; and indeed, Jewish tradition and teaching -- from the time of the giving of the Torah, never mind the later editing and redaction of the text into its final form -- has never, as in not ever, held that such a reading is even possible.Giving the Orthodox view, Moshe David Herr of The Jewish Virtual Library wrote: ORAL LAW (Heb. ×ªÖ¼×•Ö¹×¨Ö¸×” ×©×�Ö¶×‘Ö¼Ö°×¢Ö·×œÖ¾×¤Ö¼Ö¶×”), the authoritative interpretation of the Written Law (*Torah, which is the text of the *Pentateuch) which was regarded as given to Moses on Sinai, and therefore coexistent with the Written Law. This view of the Oral Law was a fundamental principle of the rabbis. The Written and Oral Laws constitute together "two that are one." "It is related that a certain man stood before Shammai and said 'Rabbi, How many Torahs have you?' The rabbi replied 'Two â€“ one written and one oral'" (ARN1 15, 61; cf. Sif. Deut. 351). There is a strong and close bond between the Written Law and the Oral Law, and neither can exist without the other â€“ both from the dogmatic point of view and from that of historical reality. The Oral Law depends upon the Written Law, but at the same time, say the rabbis, it is clear that there can be no real existence for the Written Law without the Oral. The need for the positing of the existence of the Oral Law is inherent in the very character and nature of the Torah. The statutes of the Written Law could not have been fulfilled literally even in the generation in which they were given, since "that which is plain in the Torah is obscure, all the more that which is obscure" (Judah Halevi, Kuzari, 3, 35; cf. Moses of Coucy in Semag, introduction: "For the verses contradict and refute each other," and "the statements in the Written Law are vague"). Even those statutes of the Torah that appear to be clearly formulated and detailed contain more that is obscure and requires explanation than what is manifest and understandable. The reasons given for this are many and various. The Written Law contains contradictions (cf., e.g., Deut. 16:3â€“4 with 16:8), and there is a lack of clarity and definition: The law "he shall surely be put to death" (Ex. 21:12 et al.) does not state whether by stoning, burning, or some other method not mentioned in the Torah. "And ye shall afflict your souls" (Lev. 16:31) does not indicate whether it means by mortification of the body through ascetic practices, by fasting, or in some other manner. The prohibition against doing work on the Sabbath does not specify the nature of work (see below). "And if men strive together and hurt a woman with child so that her fruit depart and yet no harm followâ€¦ But if any harm followâ€¦" (Ex. 21:22â€“23) does not make it clear whether the "harm" refers to the woman or her embryo. Dimensions and quantities are not given, e.g., in the precepts of leket, *shikhá¸¥ah, and *pe'ah, or *terumah (the priestly portion), etc. Individual laws are given without any indication of whether the law is confined to that particular case or whether it is to be regarded merely as an example of a category of laws, e.g., the law that a slave goes free if his master destroys his eye or his tooth (Ex. 21:26â€“27).
There are lacunae, and laws which are not explicitly stated but to which mere passing reference is made (thus the only reference to the laws of sale and acquisition is the prohibition against overreaching â€“ *ona'ah); there is no reference to the laws of marriage, while the law of divorce is mentioned only incidentally in connection with the injunction that a man may not remarry his divorced wife after she has remarried and become divorced again (Deut. 24:1â€“4); the Torah enjoins that one sentenced to be flogged may not have more than the fixed number of lashes inflicted (Deut. 25:1â€“3), but nowhere does it specify which transgressions involve the punishment of a flogging. From the above it seems clear that it was impossible for life to be regulated solely in accordance with the Written Law ("and I should like someone to adjudicate between two litigants on the basis of the weekly portions, Mishpatim [Ex. 21â€“24] and Ki Teáº“e [Deut. 21:10â€“25:19]" â€“ Judah Halevi, Kuzari, 3:35). It may even be inferred from the Written Law itself that immediately after it was given there already was difficulty in understanding it. Thus, e.g., it is apparent that until he heard it explicity from God, Moses did not know what the penalty was for the transgression of gathering wood on the Sabbath (Num. 15:32â€“35; cf. Sif. Zut. 15:34: "Eliezar b. Simeon says: Moses did not know that he was liable to death, nor did he know how he should be executed, as can be inferred from the reply given: 'And the Lord said unto Moses: the man shall be put to death,' i.e., he is liable to death; how shall he put to death? He [God] replied: by stoning"; cf. also the case of the blasphemer in Lev. 24:10â€“23). As stated above, there is no definition in the Pentateuch of what constitutes work in connection with the Sabbath (or the Day of Atonement), only some of the things forbidden being explicitly mentioned (plowing, reaping, kindling fire). Furthermore, in connection with the desecration of the Sabbath, in one and the same verse (Ex. 31:14) two different punishments â€“ death and *karet â€“ are given. From the point of view of its judicial literary form, the Written Law is in fact no different from other early Oriental statutes which never exhausted or aimed at exhausting all the details of the laws given.
If, therefore, the statutes of the Torah could not be properly understood in the generation in which it was given, how much less could it be understood by later generations? In addition to this consideration, it was a fundamental doctrine of the rabbis that the Torah was given by God for all time, that it would never be exchanged for another Torah and certainly never rescinded, and that it provided for all possible circumstances which might arise at any time in the future. Nevertheless, in practice, changing conditions â€“ social, economic, etc. â€“ raised many new problems, as well as the question of their solution in accordance with the Torah. The new situations and spheres of human activity which arose, for which the Written Law did not provide, could not be ignored. In fact, from the beginning the Written Law was the basis of authority of the Oral Law for the future (Deut. 17:8â€“11 and see below). It can thus be regarded as a historical fact that the Oral Law existed not merely from the moment the Written Law was given (and in this sense it is correct to say that the Written and Oral Laws were given together to Moses at Sinai), but it may even be maintained that the Oral Law anticipated the Written Law, as the Written Law not only assumes the observance of the Oral Law in the future but is in effect based on its previous existence. Since the written law relies â€“ by allusion or by its silence â€“ on statutes, customs, and basic laws not explicitly mentioned in it (marriage, divorce, business; see above), these statutes are ipso facto converted into a part of the Oral Law.
The impossibility of the Written Law existing without an Oral Law can also be demonstrated from Jewish history. The development of the Oral Law can be traced throughout the books of the Bible, especially in the prophets and the hagiographa, in the Jewish literature of the time of the Second Temple (Apocrypha and pseudepigrapha, in Jewish Hellenistic *literature, and in the early Targums of the Bible), the talmudic literature and the rabbinical literature throughout the generations (see *Halakhah). Even the dissenting sects outside normative Judaism, as long as they did not abandon Judaism completely, did not maintain the Written Law without an Oral Law: the *Sadducees possessed a "Book of Decrees â€“ who were to be stoned, who burnt, who beheaded, and who strangled" (the scholium to Megillat *Ta'anit); the Judean desert sect developed, especially by means of biblical exegesis, a most ramified halakhah which has survived in its works (in particular in the Damascus Covenant, the Manual of Discipline and other works; see Dead Sea *Scrolls); and a most ramified halakhah also developed among the *Karaites. In the relationship of the Written to the Oral Law there exists a kind of paradox, both interesting and characteristic. From the dogmatic point of view the Oral Law has its basis in, and derives its validity from, explicit verses in the Written Law, but at the same time the Written Law itself obtains its full validity and its authority for practical halakhah from the Oral Law. The Written Law in fact establishes the authority of the Oral Law by laying down that "if there arise a matter too hard for thee, thou shalt turn unto the judge that shall be in those days," and "according to the tenor of the sentence which they shall declare unto thee from that placeâ€¦ According to the law which they shall teach thee, and according to the judgment which they shall tell thee shalt thou do; thou shalt not turn aside from the sentence which they shall declare unto thee, neither to the right hand, nor to the left" (Deut. 17:8â€“11). Yet it follows precisely from those very verses themselves that it is the Oral Law itself which determines what the halakhah of the Written Law is in practice, including the true meanings (as distinct from the theoretical philological meanings) of those very verses (Deut. 17:8â€“11) themselves.
Furthermore the Oral Law lays down explicitly that from the moment of the giving of the Written Law â€“ "from Heaven," at Sinai, but in the language of men and to men â€“ it is handed over absolutely to the judgment of the human intelligence of the scholars of the Oral Law, who accept the "yoke of the kingdom of Heaven" but give halakhic ruling according to their understanding ("henceforth no prophet can innovate anything" â€“ Sifra, Be-á¸¤ukkotai, 13:7; cf. Shab. 104a), since "it is not in Heaven" (TJ, MK 3:1, 81d; BM 59b â€“ based upon Deut. 30:12). Though indeed this rule was not accepted without protest, yet those who objected belonged to the fringes of Judaism, and it was not they who determined the halakhah. The Oral Law is able to circumvent the Written Law (see TJ, Kid. 1:2, 59d). In consequence of this provision, Maimonides, following the talmudic sages, ruled that "in an emergency any bet din may cancel even the words of the (written) Torahâ€¦ in order to strengthen religion and to prevent people from transgressing the Torah. They may order flagellation and punish for breach of law, but such a ruling may not be effected permanently. Similarly, if they see a temporary need to set aside a positive precept, or to transgress an injunction in order to bring many back to religion, or in order to save many Israelites from grief in other matters, they may act in accordance with the needs of the time; just as the physician amputates a hand or a leg in order to preserve the life, so the bet din may rule at some particular time that some precept of the Torah may be transgressed temporarily in order that it may be preserved" (Yad, Mamrim 2:4). Then the sages rightly maintained that the Oral Law is the major and the main part (i.e., both in quantity and quality) of the Torah. "The Holy One made a covenant with Israel only for the sake of that transmitted orally" (Git. 60b; cf. TJ, Pe'ah 2:6, 17a: those given orally are beloved"). The Oral Law, which is well-nigh sovereign in relation to the Written Law, is the "mystery" (Î¼Î½ÏƒÏ„á½µÏ�Î¹Î¿Î½) of the Holy One (Taná¸¥. Ki Tissa 34, et al.; though the sources speak of the *Mishnah, it is certain that the whole oral law is intended) because of the essential nature of its being given orally. It is this nature of the Oral Law â€“ that it was given orally â€“ that determines its vitality and organic development; it is not immutable and fossilized but alive and evolving. This vitality, however, could only be preserved in words not fixed in writing and in a binding and unchangeable form but in words developing continually and unceasingly. As mentioned, the Sadducees had a book of decrees in writing which was their "Oral Law" (the scholium to Meg. Ta'an.), and therefore according to their outlook the whole of the Torah too was "prepared in writing" (Kid. 66a â€“ according to early printed versions and Haggadot ha-Talmud, Constantinople, 1511, 56d), i.e., the written word obligates. The Pharisees, however, claimed that the distinguishing feature and authority of the Oral Law is embedded in the fundamental rule (Deut. 31:19), "put it in their mouths" (the scholium to Meg. Ta'an.). The Oral Law was handed over to the sages, by means of whose words it is fixed and evolves from generation to generation. It is this nature and this sovereignty that are the real will of the Written Law, which was given on the basis that it be explained by means of the Oral Law. This, apparently, is the reason that although there is a disciple who expounds "more than was spoken to Moses at Sinai" (ARN2 13, 32), yet "even what a distinguished disciple will rule in the presence of his teacher was already conveyed to Moses at Sinai" (TJ, Pe'ah 2:6, 17a; cf. Meg. 19b and SEZ 2:171 "Surely both the Bible and Mishnah were communicated by the Almighty"). The meaning of all these and of similar sources is that from the point of view of its functional essence, the whole of the Oral Law was given to Moses at Sinai, since "the Torah itself gave the sages a mind to interpret and to declare" (Sif. Num. 134; cf. "matters not revealed to Moses were revealed to Akiva" â€“ (Taná¸¥. B. Num. 117; for its true meaning cf. Men. 29b â€“ the aggadah of Moses entering the yeshivah of *Akiva â€“ "and he did not know what they were saying," not even a detail of a halakhah given to Moses at Sinai). Even the Holy One repeats, as it were, a halakhah as spoken by the sages (PdRK, ed. by D. Mandelbaum (1962), 73, et al.).