Adam Clarke on Psalms 69:12

They that sit in the gate - At the gates were the courts for public justice; there were complaints lodged, and causes heard. No doubt many vexatious complaints were made against the poor captives; and false accusations, through which they grievously suffered; so that, literally, they were often "obliged to restore that which they had not taken away." See Psa 69:4.

The song of the drunkards - These poor miserable people were exposed to all sorts of indignities. Though the conduct is base, the exultation over a fallen enemy is frequent. How miserable was this lot! Forsaken by friends, scorned by enemies, insulted by inferiors; the scoff of libertines, and the song of drunkards; besides hard travail of body, miserably lodged and fed; with the burning crown of all, a deep load of guilt upon the conscience. To such a life any death was preferable.