Hadithcore
Bulugh al-Maram, 100

Narrated ‘Aisha (rad):

When the Prophet (ﷺ) came out of the privy, he used to say, “Ghufranaka (O Allah! Grant me Your forgiveness)”. [Reported by Al-Khamsa, Abu Hatim and Al-Hakim graded it Sahih (sound)].

وَعَنْهَا; { أَنَّ اَلنَّبِيَّ ‏- صلى الله عليه وسلم ‏-كَانَ إِذَا خَرَجَ مِنْ اَلْغَائِطِ قَالَ:

غُفْرَانَكَ

} أَخْرَجَهُ اَلْخَمْسَةُ.‏ وَصَحَّحَهُ أَبُو حَاتِمٍ, وَالْحَاكِم ُ [1]‏ .‏

References2 variants
In-Book Reference
Book 1, Hadith 118
English Reference
Book 1, Hadith 106