It is narrated from Sayyiduna Ka'b bin Iyad al-Ash'ari (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "If the son of Adam were given two valleys of wealth, he would wish for a third as well; nothing fills the belly of the son of Adam except dust; and Allah forgives whoever repents."
Hadith Referenceالمعجم الكبير للطبراني / باب الكاف / 16455