Elkin Bottle

The exiled card is played using the normal timing rules for its card type, as well as any other applicable restrictions such as “Cast [this card] only during combat.” For example, you can’t play the card during an opponent’s turn unless it’s an instant or has flash. Similarly, if the exiled card is a land, you can’t play it if you’ve already played a land that turn. If it’s a nonland card, you’ll have to pay its mana cost. The only thing that’s different is you’re playing it from the Exile zone.

If you do not play the card before your next upkeep, it remains exiled; you just lose the ability to play it.

To “play a card” is to either cast a spell or to put a land onto the battlefield using the main phase special action.