Sayyiduna Abu Hurayrah (may Allah be pleased with him) says that the Messenger of Allah (peace and blessings be upon him) said: "A time will certainly come upon the people when a man will not care whether he acquired wealth by lawful means or unlawful."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10402