Musannaf Ibn Abi Shayba 3:3097

Waki’ ibn al-Jarrah narrated to us, from al-Awza’i, from Musa ibn Sulayman, from al-Qasim ibn Mukhaymirah, who said: The likeness of the one who steps over the necks of the people on the day of Jumu’ah while the Imam is delivering the sermon is like one who lifts his foot into the Fire and places it into the Fire.