"Umar came in when the Ethiopians were playing in the masjid. Umar, may Allah (SWT) be pleased with him, rebuked them, but the Messenger of Allah ﷺ said: 'Let them be there, O Umar, for they are Banu Arfidah.'" (Using translation from Nasāʾī 1596)
دَخَلَ عُمَرُ وَالْحَبَشَةُ يَلْعَبُونَ فِي الْمَسْجِدِ فَزَجَرَهُمْ عُمَرُ فَقَالَ رَسُولُ اللَّهِ ﷺ «دَعْهُمْ يَا عُمَرُ فَإِنَّهُمْ هُمْ بَنُو أَرْفِدَةَ»