مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3534
Musnad of Abdullah bin Mas'ood
It was narrated from 'Abdullah bin Mas'ood (رضي الله عنه) that A man came to the Prophet (ﷺ) and said: So and so slept yesterday and missed the prayer. The Messenger of Allah (ﷺ) said: "That is (because) the Shaitan urinated in his ear - or ears.”
Musnad Ahmad 3557Its isnad is saheeh, al-Bukhari (1144) and Muslim (774)]