Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates that the Messenger of Allah (peace and blessings be upon him) said: "Among the greatest sins in the sight of Allah is that a man marries a woman and, after fulfilling his need from her, divorces her and also takes away her dowry; and a man who employs someone and then takes away his wages; and the one who kills an animal for no purpose."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14395