Al-Jinn 72:27

Illa mani irtada min rasoolinfa-innahu yasluku min bayni yadayhi wamin khalfihi rasada

Except whom He has approved of messengers, and indeed, He sends before him [i.e., each messenger] and behind him observers

except a messenger whom He chooses (to inform through revelation), and then He appoints (angels as) watching guards before him and behind him, (so that devils may not tamper with the divine revelation,)