What did the Prophet Muhammad (peace be upon him) say when `Umar came and picked up a stone and hit the Ethiopians who were playing in the Mosque?
 Narrated Abu Huraira:                     While some Ethiopians were playing in the presence of the Prophet, `Umar came in, picked up a stone and hit them with it. On that the Prophet said, "O `Umar! Allow them (to play)." Ma`mar (the subnarrator) added that they were playing in the Mosque.