It is narrated from Sayyiduna al-Agharr (may Allah be pleased with him), who was one of the Companions of the Prophet (peace and blessings be upon him), that he heard the Prophet (peace and blessings be upon him) say: "Indeed I seek the forgiveness of Allah a hundred times in a day."
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 878