It is alleged by modern critics that, while Deuteronomy was the work of some anonymous writer in the reigns of Josiah and Manasseh, the ritual portions of Exodus, Leviticus, and Numbers were the work of Ezra and the priests in Babylon. Thus, practically, the greater part of the Pentateuch is assumed to be post-exilic, and therefore not written by Moses; and this in spite of the fact that the claims of the whole Bible necessitate the Mosaic authorship.
  On the other hand, it is admitted by the same modern critics that the prophets lived and wrote in the reigns of those kings with whose reigns they are respectively associated.
  But the Pentateuch is full of technical terms and legal phraseology; and has its own peculiar vocabulary. The constant reference to these by all the prophets proves conclusively that the Pentateuch as a whole must have had a prior existence; and must have been well known by the prophets, and understood by those who heard the prophetic utterances and read the prophetic writings.
  Throughout all the books of the prophets such references to the Pentateuch have been noted in the margin of The Companion Bible with the brief indication "Ref. to Pent.", followed by the passages referred to. It is not claimed that none have been overlooked: so that the number will be greater rather than less.
  It would occupy too much space here to give the table which had been prepared. Any reader can collect the whole from the notes, and arrange them in the order of chapters and verses of the Pentateuchal books.

  An examination of these references will show that altogether 1,531 have been noted, and are distributed as follows: GENESIS is referred to 149 times; EXODUS, 312; LEVITICUS, 285; NUMBERS, 168; while DEUTERONOMY is referred to 617 times.
  Thus DEUTERONOMY, of which the modern critics have made the greatest havoc, is referred to more often than any of the other four books: 468 times more often than Genesis; 305 times more often than Exodus; 332 times more often than Leviticus; and 449 times more often than Numbers. That is to say, more often than any two of the other books put together.
  It is also remarkable that the references to technical, legal, and ritual terms are more numerous than to those relating to historical events. The latter would necessarily be better known and remembered; but the former could not have been thus referred to unless the ritual itself (less easily remembered) had existed in writing, and thus been generally known and understood. It is evident that it would have been perfectly useless for the prophets to write and quote aught but what was well known, or could be easily referred to and verified.
  Regard must also be had to the fact that the canonical order of the prophetic books is not the same as their chronological order; for Malachi (the latest prophet) refers (Malachi 1:2) to an earlier passage of Deuteronomy (Deuteronomy 7:8) than Isaiah (one of the earliest prophets), who refers, in Isaiah 1:2, to a later passage (Deuteronomy 32:1).