Musnad Ahmad 71:1

'Abbad ibn 'Abbad al-Muhallabi narrated to us, from Hisham ibn Ziyad, from 'Uthman ibn al-Arqam ibn Abi al-Arqam al-Makhzumi, from his father—and he was one of the companions of the Prophet, may Allah bless him and grant him peace—that the Prophet, may Allah bless him and grant him peace, said: "Indeed, he who steps over the necks of the people on the day of Jumu'ah, and separates between two people after the Imam has come out, is like one who drags his intestines in the Fire."