The Messenger of Allah ﷺ had relations with one of his wives, then slept while in a state of major ritual impurity until morning. He then performed the ritual bath and fasted that day.
حدثنا حماد بن خالد قال حدثنا أفلح عن القاسم
وقع رسول الله ﷺ على بعض نسائه ثم نام وهو جنب حتى أصبح ثم اغتسل وصام يومه
No references are available.
Its isnad is sahih, and it is like the one before it. Aflah is Ibn Humayd, and he is trustworthy, his hadith appearing in Sahihayn.