Sunan Ibn Majah 584
سنن ابن ماجه#584SahihIt was narrated that 'Aishah said:"When the Messenger of Allah wanted to sleep and he was sexually impure, he would perform ablution as for prayer
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Fouad Abd al-BaqiSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih Muslim
In-book reference: 1:318