You draw upon the power Pelor to seal your wounds, rather than causing more harm.

Encounter ✦     Healing
Immediate Interrupt      Personal

Trigger: An enemy would deal fire or radiant damage to you

Effect: Reduce the triggering damage to 0. You regain a number of hit points equal to the fire or radiant damage you would have taken before reducing the damage.

Published in Dragon Magazine 386, page(s) 11.