John Gill Commentary Jeremiah 44:2

"Thus saith Jehovah of hosts, the God of Israel: Ye have seen all the evil that I have brought upon Jerusalem, and upon all the cities of Judah; and, behold, this day they are a desolation, and no man dwelleth therein," — Jeremiah 44:2 (ASV)

Thus says the Lord of hosts, the God of Israel In which manner the prophecies of this book are frequently prefaced; see (Jeremiah 42:15Jeremiah 42:18) (43:10).

you have seen all the evil that I have brought upon Jerusalem, and upon all the cities of Judah; they saw it with their bodily eyes; they could not but serve it in their minds; nay, had an experimental knowledge of it; they suffered it in part themselves, and must be convicted in their own consciences that it was from the hand of the Lord:

and, behold, this day they [are] a desolation, and no man dwells therein; lie waste, at this very time; the walls are broken down the houses are demolished; the goods in them carried off; no inhabitants left, or very few, to rebuild the cities, till the land, and dwell therein.