Isaiah 26:6 - Albert Barnes' Notes on the Bible

The foot shall tread it down, even the feet of the poor - That is, evidently, those who had been despised by them, and who had been overcome and oppressed by them. The obvious reference here is to the Jews who had been captives there. The idea is not necessarily that the ‘poor’ referred to here I would be among the conquerors, but that when the Babylonians should be overcome, and their city destroyed, those who were then oppressed should be in circumstances of comparative prosperity. No doubt the Jews, who in subsequent times traveled to the site of Babylon for purposes of traffic, would trample indignantly on the remains of the city where their fathers were captives for seventy years, and would exult in the idea that their own once down-trodden city Jerusalem was in a condition of comparative prosperity. That there were many Jews in Babylon after that city began to decline from its haughtiness and grandeur, we learn expressly from both Philo and Josephus. Thus Philo (De Legatione ad Caium, p. 792) says, that ‘it is known that Babylon and many other satraps were possessed by the Jews, not only by rumour, but by experience.’ So Josephus (Ant. xv. 2.) says, that there were in the time of Hyrcanus many Jews at Babylon.