Exile the top X cards of your library. Until the end of your next turn, you may play those cards.
2/25/2015 The cards are exiled face up.
2/25/2015 Playing a card this way follows the normal rules for playing the card. You must pay its costs, and you must follow all applicable timing rules. For example, if one of the cards is a creature card, you can cast that card only during your main phase while the stack is empty.
2/25/2015 Under normal circumstances, you can play a land card exiled with Commune with Lava only if you haven’t played a land yet that turn.
2/25/2015 Any cards you don’t play will remain exiled.