Wash your face ,arms up to elbows & head before sleeping/eating while junub .

This hadith discusses the issue of ritual impurity or tahara. When a person is junub or in a state of major ritual impurity, it is permissible for them to wash their face, arms up to the elbows and head before they sleep or eat. This washing is known as wudu' and it helps purify oneself from any minor sins that may have been committed. The hadith also mentions that this washing should be done before sleeping or eating so that one can remain pure and clean when engaging in these activities. This shows us the importance of maintaining purity even when engaging in everyday activities such as sleeping and eating.