Sunan an-Nasa'i 404
سنن النسائي#404SahihIt was narrated that 'Abdullah bin Abi Qais said:"I asked 'Aishah: 'How did the Messenger of Allah (ﷺ) sleep while he was Junub? Did he perform Ghusl before sleeping or sleep before performing Ghusl?' She said: 'He did both. Sometimes he would perform Ghusl then sleep, and sometimes he would perform Wudu' then sleep
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 4:9