Musannaf Ibn Abi Shayba 1:657

Abu Bakr narrated to us, he said: Ibn 'Uyaynah narrated to us, from al-Zuhri, from Abu Salamah, from 'Aishah, that the Prophet (may Allah bless him and grant him peace), when he wanted to sleep while he was in a state of janabah (major ritual impurity), he would perform wudu (ablution) like his wudu for prayer.