Aisha was asked about a man who wakes up in a state of major ritual impurity while intending to fast. She said, "The Messenger of Allah ﷺ used to wake up in a state of major ritual impurity from intercourse, not from a wet dream, then he would perform the ritual bath and complete his fast."
حدثنا علي بن محمد حدثنا عبد الله بن نمير عن عبيد الله عن نافع قال
عن الرجل يصبح وهو جنب يريد الصوم قالت كان رسول الله ﷺ يصبح جنبا من الوقاع لا من احتلام ثم يغتسل ويتم صومه
[Its isnad is sahih] Tabarani transmitted it (Kabir: 23/291, no. 642) from the hadith of Ubaydullah bin Umar, through him, and it has corroborating narrations in Muslim, no. 1109, and elsewhere.