Utica

Hideaway (This land enters the battlefield
tapped. When it does, look at the top four cards
of your library, exile one face down, then put the
rest on the bottom of your library.)
{t}: Add {g} to your mana pool.
{g}, {t}: You may play exiled card without
paying its mana cost if creatures you control
have a total power of 10 or greater.