Albert Barnes Commentary Judges 3:8

"Therefore the anger of Jehovah was kindled against Israel, and he sold them into the hand of Cushan-rishathaim king of Mesopotamia: and the children of Israel served Cushan-rishathaim eight years." — Judges 3:8 (ASV)

Here we resume the thread of the main narrative, which seems as though it should have run as follows (Judges 1:1): Now, etc. (Judges 3:8), therefore (or “and”) etc.

Served Chushan-Rishathaim - This is the same phrase as in (Judges 3:14). From it is derived the expression, “the times of servitude,” as distinguished from “the times of rest,” in speaking of the times of the Judges.

Mesopotamia, or Aram-naharaim, was the seat of Nimrod’s kingdom, and Nimrod was the son of Cush (Genesis 10:8–12). Rishathaim is perhaps the name of a city, or a foreign word altered to a Hebrew form. Nothing is known from history, or the cuneiform inscriptions, of the political condition of Mesopotamia at this time, though Thotmes I and III in the 18th Egyptian dynasty are known to have invaded Mesopotamia.

It is, however, in accordance with such an aggressive Aramean movement toward Palestine that, as early as the time of Abraham, we find the kings of Shinar and Elam invading the south of Palestine. There is also distinct evidence in the names of the Edomite kings (Genesis 36:32), (Genesis 36:35), and (Genesis 36:37) of an Aramean dynasty in Edom around the time of the early Judges.

Compare also Job 1:17.