Aisha reported that whenever the Prophet ﷺ came out from relieving himself, he would say, "I seek Your forgiveness."
إن النبي ﷺ كان إذا خرج من الغائط قال: غفرانك.
No references are available.
Abu Dawud (30), Tirmidhi (7), and Ibn Majah (300) narrated it, and Ibn Khuzayma (90), Ibn Hibban (1444), and Hakim (1/158) graded it sahih, all of them through the route of Israil bin Yunus, from Yusuf bin Abu Burda, from his father, from Ayesha, and I mentioned it. Tirmidhi said, "Hasan gharib, we do not know it except through the hadith of Israil from Yusuf bin Abu Burda." He also said, "We do not know of anything in this chapter except the hadith of Ayesha from the Prophet ﷺ." Hakim said, "This is a sahih hadith, for Yusuf bin Abu Burda is among the trustworthy members of the household of Abu Musa, and we have not found anyone who criticized him, and it has been mentioned that his father heard directly from Ayesha."I say, its chain is hasan because of Yusuf bin Abu Burda, for Ajli, Ibn Hibban, and Hakim all deemed him trustworthy, and no criticism of him is known, so someone like him makes his hadith hasan. The discussion of this is set out at length in the Book of Purification.