refuse to administer an oath to anyone who asked for it. He would administer the oath to every claimant who requested it, and we require it only when there is a plausible indication—comparable to the degree of evidence that obliges payment in financial claims.
Abū al-Zinād explained that he meant situations of close dealings, physical involvement, or any credible suspicion. Mālik said, “Such is the practice among us.” A group of the scholars of Madinah hold that the oath is binding upon every defendant and that prior dealings need not be established. Accordingly, if a judge or a mufti imposes the oath without proof of such dealings, basing himself on the outward wording and general scope of the ḥadīth, he is not deemed to have departed from it.
The formula of the oath that the defendant must pronounce is: “By Allah,” or “By Allah, besides Whom there is no deity,” or “By Allah, there is no god but He.” He must not add anything beyond that. This, according to Mālik, is the wording used in every case where an oath is required, whether concerning individual rights or in qiṣāmah (the collective oath in murder investigations). No oath is admissible in any of the ḥadd penalties (fixed corporal punishments) except in qiṣāmah and in the oaths of liʿān (mutual imprecation between spouses).
Moreover, in the view of Mālik and his companions, an oath is not imposed merely because a claim has been filed, except in matters for which the testimony of two women together with one man is acceptable. If a person acknowledges a debt to another, or evidence is produced against him, and he then claims to have repaid it, the creditor must swear that he has not been paid. If the creditor refuses to swear, the defendant takes the oath and the claim against him is dismissed. Should the defendant then refuse to swear, the liability reverts to him and his allegation is rejected.
If the creditor dies, his heirs swear that, to the best of their knowledge, their deceased never received the debt, in whole or in part; once they do so, the right is established in their favor. If they decline to swear, the debtor takes the oath and is released from liability.
Ibn Abī Uways transmitted from Ibn Wahb, who related it from Mālik, that in a dispute over a loan or a debt the defendant swears, “He has no claim upon me regarding what he alleges against me.” Ibn Wahb added that he should also say, “and what he alleges is nothing but falsehood,” whereupon he is exonerated. He is not required to swear, “You did not lend me anything.” This is likewise the opinion of ʿAbd al-Malik and his son ʿAbd al-ʿAzīz.