Write it before them in a tablet; i.e." write the prophecy before them" (equivalent to "to be set up before them") "on a tablet," in the briefest possible form (comp. Isaiah 8:1). And note it in a book; i.
e. "and also make a full notation of it in a book," or parchment roll. The "tablet" was to be for the admonition of the living generation of men; the "book" was for future generations, to be a record of God's omniscience and faithfulness "forever and ever."
That it may be for the time to come; rather, for an after-day—not for the immediate present only. For ever and ever. Modern critics observe that the phrase, la'ad 'ad 'olam, never occurs elsewhere, and suggest a change of the pointing, which would give the sense of "for a testimony forever."
Whether we accept the change or not, the meaning undoubtedly is that consigning the prophecy to a "book" would make an appeal to it possible in perpetuum. The perpetuity of the written Word is assumed as certain.