It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both), he says: I was sitting with the Messenger of Allah (peace and blessings be upon him), I heard him seek forgiveness one hundred times and then make this supplication: "Allahumma ighfir li warhamni, wa tub 'alayya, innaka anta at-Tawwab ar-Raheem." (O Allah! Forgive me, have mercy on me, and turn towards me; surely, You are the Most-Relenting, Most-Merciful.) In one narration, at the end, the words are: "Innaka Tawwabun Ghafoor."