It is narrated from Ibn e Umar [RA] that the Messenger of Allah (SAW) said, “Purify these bodies, and Allah will purify you. Whenever a slave spends his night in a state of purification, an angel spends his night within his (slave’s) hair and he does not turn over during the night except that he [the angel] says: O Allah, forgive Your slave, for he went to sleep in a state of purification.” [Reported by Tabarani and graded "good" by Shaikh Al-Albani]