What is the ruling on killing due to jealousy over one's wife or beloved?

Killing a soul unjustly is among the gravest sins and greatest crimes, for Allah Almighty says: "Whoever kills a soul unless for a soul or for corruption [done] in the land - it is as if he had killed all of mankind" and "But whoever kills a believer intentionally - his recompense is Hell, wherein he will abide eternally." The Prophet, peace and blessings be upon him, also counted it among the gravest sins.

The blood of a Muslim is sacred and it is not permissible to kill him except for one of three reasons: a life for a life, a married fornicator, and one who abandons the religion and separates from the community. And this must be by a decision from the ruler, not individuals.

If a man finds someone committing adultery with his wife, his killing of that person is not accepted Islamically unless there is clear evidence of adultery. However, concerning what is between him and Allah Almighty, if he is truthful, then there is no blame upon him. A distinction must be made between the apparent ruling and the hidden ruling.

Jealousy for one's wife and mahrams is praiseworthy if it is due to suspicion and does not exceed the bounds of moderation. However, if it exceeds these bounds, it is blameworthy.