Rule 419.3

Healing is a Limited Action.

• 419.3.a Players may only Heal units when game effects instruct them to, or at specific points in the turn.

Rulings that cite this rule

• What happens when a card like The Harrowing instructs me to play another card during its resolution? Do I play it while the other spell or ability is still resolving? What if I can’t play it?
• So how exactly does this ability work?
• What about Dazzling Aurora? If I reveal Nocturne, do I get to play him and keep going?

Official Core Rules