Aisha reported that she missed the Prophet ﷺ from his bed, so she searched for him with her hand and found him prostrating, saying, "Lord, grant my soul its piety and purify it, for You are the best to purify it. You are its Guardian and Protector."
حدثنا وكيع عن نافع يعني ابن عمر عن صالح بن سعيد
أنها فقدت النبي ﷺ من مضجعه فلمسته بيدها فوقعت عليه وهو ساجد وهو يقول رب أعط نفسي تقواها زكها أنت خير من زكاها أنت وليها ومولاها
No references are available.
Its isnad is sahih, it has already been mentioned at 19204.