Before sleeping, we are taught to recite the masnoon duas and remember Allah Ta‘ala. Among the masnoon duas before sleeping, is the following dua:

اَللّٰهُمَّ بِاسْمِكَ أَمُوْتُ وَأَحْيٰى

O Allah, with Your name do I die and live. ^[1]

In this dua, sleep has been resembled to death, due to the fact that when a person sleeps, he loses his senses and consciousness.

Hence, from this dua, we are being taught that at the time of sleeping, one should be prepared to meet Allah Ta‘ala.