Jamieson, Fausset and Brown on Jeremiah 25:20

20. mingled people--mercenary foreign troops serving under Pharaoh-hophra in the time of Jeremiah. The employment of these foreigners provoked the native Egyptians to overthrow him. Psammetichus, father of Pharaoh-necho, also had given a settlement in Egypt to Ionian and Carian adventurers [Herodotus, 2.152, 154]. (Compare Jr 50:37; see on Is 19:2, 3; Is 20:1; Eze 30:5. The term is first found in Ex 12:38.

Uz--in the geographical order here, between Egypt and the states along the Mediterranean; therefore not the "Uz" of Job 1:1 (north of Arabia-Deserta), but the northern part of Arabia-Petræa, between the sea and Idumea (La 4:21; see Ge 36:20, 28).

remnant of Ashdod--called a "remnant," because Ashdod had lost most of its inhabitants in the twenty-nine years siege by Psammetichus. Compare also see on Is 20:1. Gath is not mentioned because it was overthrown in the same war.