This prophecy Jeremiah 48 is an amplification of Isa. 15–16, and also introduces two verses, Jeremiah 48:43-44, from Isaiah 24:17-18. Jeremiah’s introduction of passages from older writers being accepted, it would seem that the passages borrowed are so inwoven with that which is Jeremiah’s own, that they cannot be omitted as a later interpolation without destroying the whole. On the other hand in that which is the writer’s own, and even in many of the alterations of the borrowed passages, Jeremiah’s mode of expression is so clearly to be recognized that the whole must be acknowledged to be his.
From Isaiah 16:13 it has been conjectured that Isaiah had an ancient prophecy before him, and that Jeremiah drew from the same source. Bearing in mind the number of prophetic writings mentioned in the Books of Chronicles which have not come down to us, there is nothing unreasonable in such a supposition.