(79) باب اللَّهْوِ بِالْحِرَابِ وَنَحْوِهَا
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 (ﷺ) said, "O `Umar! Allow them (to play)." Ma`mar (the subnarrator) added that they were playing in the Mosque.
Reference: Sahih al-Bukhari 2901
In-book reference: Book 56, Hadith 115
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 4, Book 52, Hadith 150