Miracle is a keyword ability.
You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.
Most often, the first card you draw on your turn is at your draw step. However, this ability can be triggered on your opponents turn when you cast an instant that lets you draw cards, like Think Twice. If you cast a spell that lets you draw multiple cards at once, it will still trigger, but only if it was the first card you drew from the spell. That means that there are few rules when you draw a miracle card. It may not touch the other cards in your hand and then be revealed. Because some players could take a miracle card that was already in their hand and switch it with the card they just drew, which is obviously cheating.
- 702.93a Miracle is a static ability linked to a triggered ability (see rule 603.10). “Miracle [cost]” means “You may reveal this card from your hand as you draw it if it’s the first card you’ve drawn this turn. When you reveal this card this way, you may cast it by paying [cost] rather than its mana cost.”
- 702.93b If a player chooses to reveal a card using its miracle ability, he or she plays with that card revealed until that card leaves his or her hand, that ability resolves, or that ability otherwise leaves the stack.