Adam Clarke on Ezekiel 23:23

Pekod, and Shoa, and Koa - פקוד ושוע וקוע. These names have been thought to designate certain people bordering on the Chaldeans; but no geographer has ever been able to find them out.

In our old translations these names were considered appellatives - rulers, mighty men, and tyrants. Others, following the literal import of the words, have translated, visiting, shouting and retreating. Others have applied them to the habits of the Chaldean soldiers. Pekod signifying the muster or review of armies; Shoa, the magnificence of their uniform and arms; and Koa, the marks or embroidery of the clothes of the captains and generals. Grotius thought that they might be names of contiguous nations: Pekod, the Bactrians; Shoa, a people of Armenia; and Boa, the Medes. I have nothing to add that would satisfy myself, or be edifying to my readers.