Sayyiduna Abu Hurayrah (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "Whoever asks people for their wealth to increase his own is only asking for a live coal, whether he takes little of it or much."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7871