Perform wudu' before sleeping while junub.

This hadith explains that it is permissible for a person to sleep while in a state of ritual impurity or Junub as long as they perform ablution or Wudu' beforehand. This means that if someone has performed an act which requires them to take a bath before they can pray such as sexual intercourse, then they can still go to bed and rest without taking the bath first. However, it is important for them to perform the ablution before sleeping so that their prayer will be accepted when they wake up and are ready to pray. The Prophet Muhammad ﷺ taught us this lesson so that we can make sure our prayers are accepted even when we are not able to take a full bath right away.