It is narrated from Sayyiduna Samurah bin Jundub (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "Whoever misses a Jumu'ah without an excuse, let him give a dinar in charity; and if he cannot find it, then let him give half a dinar in charity."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6949