Alrund's Epiphany

Casting a foretold card from exile follows the timing rules for that card. If you foretell an instant card, you can cast it as soon as the next player's turn. In most cases, if you foretell a card that isn't an instant (or doesn't have flash), you'll have to wait until your next turn to cast it.

Exiling Alrund's Epiphany as it resolves is part of its effect. If Alrund's Epiphany doesn't resolve, it will be put into its owner's graveyard. If it's exiled this way, it's exiled face up and doesn't become foretold.

Because exiling a card with foretell from your hand is a special action, you can do so any time you have priority during your turn, including in response to spells and abilities. Once you announce you're taking the action, no other player can respond by trying to remove the card from your hand.