Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) said that Sayyiduna Umar (may Allah be pleased with him) told the Messenger of Allah (peace and blessings be upon him) that he would become junub (in a state of major ritual impurity), and the Messenger of Allah (peace and blessings be upon him) said: "Perform ablution, wash your private part, and then sleep."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 14092
Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) said that Sayyiduna Umar (may Allah be pleased with him) said: O Messenger of Allah (peace and blessings be upon him)! If I become junub, what should I do? He (peace and blessings be upon him) said: "Wash your private part, perform ablution, then sleep."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 14093
Sayyidah Aishah (may Allah be pleased with her) said: When the Messenger of Allah (peace and blessings be upon him) was junub and wished to sleep or eat, he would perform ablution.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 14094