مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2536
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated from Ibn 'Abbas (رضي الله عنه) that the Prophet (ﷺ) came out of the outhouse and some food was brought. It was said to him: Aren't you going to do wudoo’? He said: “I have only been commanded to do wudoo’ when I get up to pray."
Musnad Ahmad 2549Its isnad is saheeh, Muslim (374)]