The Messenger of Allah ﷺ would sometimes rise in the morning in a state of major ritual impurity from being with his family, then he would bathe before praying Fajr and fast that day.The narrator said, I mentioned this to Abu Hurairah, and he said, "I do not know. Fadl bin Abbas, may Allah be pleased with him, is the one who informed me of that."
حدثنا يعقوب حدثنا ابن أخي ابن شهاب عن عمه قال أخبرني أبو بكر بن عبد الرحمن بن الحارث بن هشام قال
قد كان رسول الله ﷺ يصبح من أهله جنبا فيغتسل قبل أن يصلي الفجر ثم يصوم يومئذ قال فذكرت ذلك لأبي هريرة فقال لا أدري أخبرني ذلك الفضل بن عباس رضي الله تعالى عنه
No references are available.
Its isnad is sahih. Bukhari related it, 4:123-125, through Malik from Sumayy from Abu Bakr Ibn Abdul-Rahman, and through Shuayb from Zuhri from Abu Bakr bin Abdul-Rahman, at greater length. Muslim also related it at greater length, 1:305-306, through Ibn Jurayj from Abu Bakr bin Abdul-Rahman, 1826.