It is narrated from Sayyiduna Jabir (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "Whoever believes in Allah and the Last Day, the Friday prayer is upon him on Friday, except for a sick person, a traveller, a child and a slave. And whoever considers himself free of need of it because of amusement or trade, Allah will be free of need of him, and Allah is Free of need, Praiseworthy."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجمعة / 5634