Silsilat al-Ahadith al-Sahihah

Sayyiduna Abdullah bin Amr (may Allah be pleased with him) narrates: The Messenger of Allah (peace and blessings be upon him) instructed a man to lead the people in the Zuhr prayer. While leading the prayer, he spat in the direction of the Qiblah. When the time for Asr prayer came, the Prophet (peace and blessings be upon him) sent another man (to lead the prayer). The first man became afraid and came to the Prophet (peace and blessings be upon him) and said: O Messenger of Allah! Has any command been revealed concerning me? The Prophet (peace and blessings be upon him) replied: "No, (no command has been revealed, the matter is that) when you were leading the people in prayer, you spat in front of you and thus caused harm to Allah and the angels (this is the reason you were set aside)."