Sayyiduna Abu Ju'd Damri (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: "Whoever leaves three Jumu'ahs without a valid Shari'ah excuse..." In Ibn Idris's narration, it is: "then a seal is set upon his heart." And in the narration of Waki', it is: "then that person is a hypocrite."