Psalm 35 is one of those psalms where the poet is surrounded by enemies seeking his downfall. These enemies "repay evil for good," they "gather in glee" to mock, they hate the poet "without cause," they "do not speak in friendly ways but devise fraudulent schemes."
Basically, it's a pretty awful social situation.
As commentators have long noted, salvation in the Old Testament is this-worldly. There is no heaven or hell. Just the rewards and goods of this life. And one of those rewards in Psalm 35 is vindication. Standing before lies, mockery, gossip, accusations, and ridicule and having all that speech stop.
I have no great insight here, other than to observe the deeply relational and social vision of salvation Psalm 35 puts before us. Liberation for the poet isn't the forgiveness of sins but the restoration of a peaceable community. Something needs to be set right, not just with ourselves, but with our society. Many of the prayers in the Psalms, like Psalm 35, concern social strife and conflict. The tearing of shalom. And as I look at our world, at all our conflict and strife, a world where people do not speak in friendly ways, I think a little this-worldly salvation just might be exactly what we need.
Or stated more simply: I don't want anyone to go to hell, but I do wish a lot of people would just stop talking.