2nd-level necromancy (ritual)
Casting Time: 1 action
Components: V, S, M (a pinch of salt and one copper piece placed on each of the corpse’s eyes, which must remain there for the duration)
Duration: 10 days
As per this Gentle Repose dnd 5e spell you can touch the corpse or else even some other remains. For a specific duration, the target has been protected from the decay and it can not become undead. Even the spell can also be effectively extends its time limit on rising its target from the dead, since some days spent under an influence of this spell do not count against to the time limit of the spells like the raise dead.
Spell Lists: Cleric, Wizard