Musnad Ahmad 1153:2065

Rawh narrated to us, he said: Malik narrated to me, from Abdullah ibn Abd al-Rahman ibn Ma'mar al-Ansari, from Abu Yunus, the freed slave of Aisha, from Aisha, that a man said to the Messenger of Allah, peace and blessings of Allah be upon him, while he was standing at the door: "O Messenger of Allah, I wake up in a state of janabah (major ritual impurity), and I want to fast." The Messenger of Allah, peace and blessings of Allah be upon him, said: "And I wake up in a state of janabah, and I want to fast, then I perform ghusl (ritual bath) and fast." The man said: "You are not like us, for you have been forgiven your past and future sins." The Messenger of Allah, peace and blessings of Allah be upon him, became angry and said: "By Allah, I hope that I am the most fearful of you of Allah, and the most knowledgeable of what I must guard against."