Holy Ground

You invoke divine powers to bless the ground within 60 feet of you. Creatures slain in the affected area cannot be raised as undead by magic or by the abilities of monsters, even if the corpse is later removed from the area. Any spell of 4th level or lower that would summon or animate undead within the area fails automatically. Such spells cast with spell slots of 5th level or higher function normally.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the level of spells that are prevented from functioning increases by 1 for each slot level above 5th.