Thought Lash | Magic: The Gathering
Formats Thought Lash is Legal in
Official Oracle Text for Thought Lash
When a player doesn't pay Thought Lash's cumulative upkeep, that player exiles all cards from his or her library.
Exile the top card of your library: Prevent the next 1 damage that would be dealt to you this turn.
Official Rulings for Thought Lash
10/1/2008 : If your library has no cards in it, you can't activate the last ability.