Fortress of the Muslim (Hisn al-Muslim)
حصن المسلم
(7) Chapter: After leaving the bathroom
(7) دعاء الخروج من الخلاء
Hisn al-Muslim 11 
Ghufrānaka I seek Your forgiveness. Reference: Abu Dawud, Ibn Majah and At-Tirmidhi. An-Nasa'i recorded it in 'Amalul-Yawm wal-Laylah. Also see the checking of Ibn Al-Qayyim's Zadul-Ma'ad, 2/387.
غُفْـرانَك
Reference : Hisn al-Muslim 11