Sayyiduna Ibn Umar (may Allah be pleased with them both) said that the Messenger of Allah (peace and blessings be upon him) said: "Allah Almighty does not accept charity from wealth gained through treachery, nor (does He accept) prayer without purification."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 187