Muwatta Imam Malik (Riwayat Ibn al-Qasim)

It is narrated from the wife of the Prophet, Aisha (may Allah be pleased with her), that the Messenger of Allah (peace and blessings be upon him) was standing by the door when a man said to him: "O Messenger of Allah! I become junub (in a state of major ritual impurity) at night and I intend to fast?" So the Messenger of Allah (peace and blessings be upon him) said: "I also become junub at night and I intend to fast, so I perform ghusl (ritual bath) and then fast." The man said: "O Messenger of Allah! You are not like us; Allah has placed a veil between you and sins, both before (prophethood) and after, that is, you are completely free from sins." Upon this, the Messenger of Allah (peace and blessings be upon him) became angry and said: "By Allah! I hope that I am the most God-fearing among you and the one who knows His limits best among you."