1034 – From a man of the Anṣār (may Allah be pleased with him): “The Messenger of Allah ﷺ kept qasāmah in force exactly as it had existed during the pre-Islamic era, and the Messenger of Allah ﷺ ruled by it between a group of the Anṣār concerning a man who had been slain and whom they accused the Jews of killing.” Narrated by Muslim (1).
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Points derived from the ḥadīth:

1. In Islamic law, qasāmah is a series of repeated oaths taken in a claim of killing a person whose life is inviolable.
2. Ibn Qutaybah said: The first to judge by qasāmah in the Age of Ignorance was al-Walīd ibn al-Mughīrah; the Prophet ﷺ then ratified it in Islam. Thus Islam endorses words and deeds that realize a benefit or whose benefit outweighs the harm.
3. The ḥadīth shows that qasāmah was affirmed in the very form in which it had been practiced, and that the Prophet ﷺ applied it among some of the Anṣār, as will appear in the narration of Sahl ibn Abī Ḥathmah after this ḥadīth, if Allah the Exalted wills.
4. Some scholars contend that qasāmah departs from legal analogy, for normally the burden of proof rests with the claimant and the oath with the one who denies, whereas qasāmah reverses the arrangement and requires the oaths of the claimant or claimants.
5. Careful consideration, however, shows that qasāmah is fully consistent with analogy. The rule is that the oath belongs to the stronger of the two sides in a dispute, and qasāmah is invoked only when accompanied by a strong indication that supports the claim and reinforces the charge against the defendant. At that point the oath is assigned to the claimant, because his side has been strengthened by the circumstantial evidence.