Musnad Ahmad 1166:5

Hammad ibn Usamah narrated to us, he said: Hatim ibn Abi Saghirah informed me, and Rawh, he said: Hatim ibn Abi Saghirah narrated to us, he said: Simak ibn Harb narrated to us, from Abu Salih, the freed slave of Umm Hani. Rawh said in his narration: Umm Hani narrated to me, she said: I asked the Messenger of Allah (peace and blessings of Allah be upon him) about the saying of Allah the Exalted: "And you commit evil in your gatherings" [Al-Ankabut: 29]. He said: "They used to throw pebbles at the people of the road and mock them, and that is the evil which they used to commit." Rawh said: And that is the saying of Allah the Exalted: "And you commit evil in your gatherings" [Al-Ankabut: 29].