Musannaf Ibn Abi Shaybah 9014 — Disbelievers entering the mosque

Al-Hasan said: When the delegation of Thaqif came to the Prophet (peace and blessings be upon him), they were lodged in the rear part of the mosque. When the time of prayer came, a man said: "O Messenger of Allah, the time of prayer has come, and these are disbelievers and they are in the mosque." The Messenger of Allah (peace and blessings be upon him) said: "Nothing makes the earth impure."