Sayyiduna Abu Qatadah (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "Whoever abandons Jumu'ah three times without any necessity, a seal is placed upon his heart."
Imam Ahmad recorded it, and its chain is hasan (good).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 3173