"Don’t hold the iniquities of our forefathers against us" (79:8), and then "forgive our sins" (79:9). Whose sins does the psalm mean?

In the WEB the psalm names both. It asks, "Don’t hold the iniquities of our forefathers against us" (79:8), and in the next verse, "Deliver us, and forgive our sins, for your name’s sake" (79:9). It doesn't say which sins, or that any sin brought about what 79:1-3 tells, and these notes don't say so either: nothing here says the dead of 79:2-3 died for their sins. Lamentations has both kinds of words too: "Our fathers sinned, and are no more. We have borne their iniquities" (Lamentations 5:7), and a few verses on, "Woe to us, for we have sinned!" (Lamentations 5:16). What the psalm asks rests on God's mercy and his name: "Let your tender mercies speedily meet us, for we are in desperate need" (79:8), and "for the glory of your name" (79:9).