The Messenger of Allah ﷺ would enter the morning in a state of major ritual impurity not caused by a wet dream, and then he would fast.
حدثنا عبد الوهاب الثقفي قال حدثنا أيوب عن محمد
أن رسول الله ﷺ كان يصبح جنبا من غير احتلام ثم يصوم
Its isnad is sahih. It was mentioned previously in 25370.