Matthew Poole and continuators on Jeremiah 46:20

20 Egypt is like a very fair heifer, but destruction cometh: it cometh out of the north .

That is, Egypt is now in a thriving prosperous condition, having not used to be under any yoke like an Heifer, that is fair, and fat but she will not be so long, she is but as a beast fatted for the slaughter, and there are slaughter men, coming out of Caldea that will kill this fair Heifer and make her a sacrifice to the Justice of God.