Musnad Ahmad 1034:180

Waki’ narrated to us, Sufyan narrated to us, from Abu Ishaq, from ‘Ubayd Abu al-Mughirah, from Hudhayfah, who said: There was a sharpness in my tongue toward my family, and that would not extend beyond them to others. I complained of that to the Prophet, peace and blessings of Allah be upon him. He said: "Where are you regarding seeking forgiveness, O Hudhayfah? Verily, I seek forgiveness from Allah one hundred times a day."