It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "The greatest sins (i.e., the greatest sinners) are: (1) The man who marries a woman, fulfills his need with her, then divorces her and usurps her dowry. (2) The man who employs someone for work and consumes his wages himself. And (3) the man who kills an animal without benefit."