Question: Is it permissible for one who is junub to sleep before making wudhoo.?
Response: There is no sin upon him if he slept without making wudhoo. However, it is better that he makes wudhoo. before he sleeps, as the Prophet (sal-Allaahu `alayhe wa sallam) did this and encouraged it.
And with Allaah lies all success and may Allaah send prayers and salutations upon our Prophet (sal-Allaahu `alayhe wa sallam) and his family and his companions.
The Permanent Committee for Islaamic Research and Fataawa