MTGNexus

I've damaged a player with Hope of Ghirapur and sacrificed it. If I have a way of getting Hope of Ghirapur back from my graveyard, can I sacrifice it again? Or has it been "stamped"?

Nope. The Hope that dealt damage was sacrificed and is now a new object in the graveyard. You return it but it is still a new object on the battlefield which means it is not the same one that dealt damage. You would need to deal combat damage with the *new* one in order to sac it.

And even if you manage to bring it back after activating his ability, and have an additional combat phase sacrificing it again will net you no gain as the ability does not stack (unless you are in multiplayer and hit a different player in your second combat)