John Gill Commentary Ezekiel 32:16

"This is the lamentation wherewith they shall lament; the daughters of the nations shall lament therewith; over Egypt, and over all her multitude, shall they lament therewith, saith the Lord Jehovah." — Ezekiel 32:16 (ASV)

This is the lamentation with which they shall lament her
The Egyptians themselves, or rather they that are after mentioned. The Targum is, ``the prophet said, a lamentation is this prophecy, and it shall be for a lamentation;'' he was bid at the beginning of it to take up a lamentation, and now at the end of it he pronounces it to be one, and that it should be sung as such:

the daughters of the nations shall lament for her ;
either literally understood, it being the business and custom of women to say or sing the funeral dirge, or the lamentation at the interment of the deceased; or figuratively, the inhabitants of other nations. So Ben Melech and the Targum, ``the villages of the people shall lament her''; that is, the inhabitants of them, who were in alliance with Egypt, and under its protection:

they shall lament for her, even for Egypt, and for all her multitude ;
for the desolation of the land, and for the vast numbers of people that should be slain with the sword, or carried captive:

says the Lord God ;
which is added for the confirmation of it; for what he has spoken shall be done.