You touch a corpse or other remains. The target is protected and free from decay and cannot be transformed into an undead creature for the duration of the spell.

Gentle Repose 5e

Level: 2nd

Classes: Wizard, Cleric

Casting Time: 1 Action

Range: Touch

Components: V, S, M

Duration: 10 days

This spell also effectively extends the time limit for resurrecting a target, as time spent under the spell’s influence does not count against the time limit of spells such as raise dead.