John Gill's Exposition of the Whole Bible
Jeremiah 29:16
[Know] that thus saith the Lord,.... Or "for", or "wherefore thus saith the Lord" x; for the word "know" is not in the text, and seems needless; though it is also supplied by other interpreters y. The words are illative, and follow upon the former; and the sense is, that since they gave heed to their false prophets in Babylon, who told them that they should quickly return; therefore the Lord sent the following message to them, informing them that it was so far from being true that they should in a short time return to Jerusalem, that, on the other hand, they that were there should soon be with them in captivity, or be destroyed:
of, or "concerning"
the king that sitteth on the throne of David; that is, King Zedekiah, who was then the reigning king at Jerusalem:
and of all the people that dwelleth in this city; the city Jerusalem, where Jeremiah was, and from whence this letter was written, in the name of the Lord, to the captives at Babylon:
and of your brethren that are not gone forth with you into captivity; that lived in the several parts of the land of Judea, who were left behind, and not carried captive, when those were to whom these words are directed.
x כי כה אמר "nam sic ait", Junius Tremellius, Piscator, Cocceius "ideo", Calvin; "ita namque", Schmidt. y "Scitote quod", Vatablus.