Can someone help me settle this?

Question

I was playing Magic: The Gathering with one of my brothers. He plays a Green Instant called "Reclaim," which allows you to take a card from your graveyard and put it on top of your library. Well, I asked him what card it was he chose, and he said he didn't have to tell me. My argument, of course, is that the graveyards are public and its contents must be made known if requested. I asked him as if before the effect of the card wasn't yet fulfilled, so one of my other brothers says the card is already on top and he doesn't have to tell me. But, I asked before the effect was fulfilled. Who would be right?

Answer 1

You are correct - he has to name the target as he is casting the spell.

Reclaim actually states: Put target card from your graveyard on top of your library.

He has to name the target as he casts the spell, then you get to watch to make sure he chooses the right card.