Your chanting creates a wave of positive energy that spreads out from you, curing 1 point of damage per two caster levels (maximum 5 points) each round to all living creatures in the area of effect. Because undead are powered by negative energy, this spell deals such creatures a like amount of damage rather than curing them. If an undead creature makes a successful save, it is immune to the effects of that particular casting of the spell (even if it leaves the emanation but later enters it again). Undead that fail their saves stop taking damage if they leave the area, but resume taking damage if they enter it again later.