It is narrated from Sayyiduna al-Arqam (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever steps over the necks of people on the day of Jumu'ah and separates them is like one who drags his intestines in Hellfire."
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 904