Spinerock Knoll

Hideaway 4 (When this land enters the battlefield, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Spinerock Knoll enters the battlefield tapped.
T: Add R.
R, T: You may play the exiled card without paying its mana cost if an opponent was dealt 7 or more damage this turn.