It is narrated from Sayyiduna Jabir bin Abdullah (may Allah be pleased with both of them) that the Noble Prophet (peace and blessings of Allah be upon him) said: "Whoever, without necessity, misses three Fridays, Allah Almighty sets a seal upon his heart."
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."