The reason for this divergence lies in the competing claims of equity between the two parties. If no guarantor is taken merely on the basis of an allegation, the defendant may disappear and the claimant be wronged; yet if a guarantor is taken immediately, the allegation may prove unfounded and the defendant will suffer injustice. For this reason some jurists differentiate between a claimant whose evidence is present and one whose evidence is absent.

It is related from ʿUrāk ibn Mālik:

“A company of Bedouins came bringing their mounts. Two men joined them and spent the night with them. Come morning, the Bedouins found that several of their camels were missing. The Messenger of God—peace and blessings be upon him—said to one of the two men, ‘Go after them,’ and he detained the other. The man went off and returned with what had been taken. The Messenger of God—peace and blessings be upon him—then said to one of the two men, ‘Seek forgiveness for me.’ He replied, ‘May God forgive you.’ The Prophet said, ‘And you—may God forgive you and grant you martyrdom in His cause.’ ”

Abū ʿUbayd recorded this ḥadīth in his work on jurisprudence. He adds: Some scholars regarded the Prophet’s action as imprisonment, but I do not approve of that interpretation, for imprisonment is not warranted by a mere claim. Rather, I see it as a form of suretyship for a right that had not yet been established, given the suspicion arising from the two men’s having traveled with the Bedouins.

As for the classes of persons on whose behalf suretyship may be undertaken, no widely noted dispute arises except over guaranteeing a deceased debtor who has left no estate to settle his debt. Mālik and al-Shāfiʿī consider such a guarantee valid, whereas Abū Ḥanīfah deems it impermissible.

Abū Ḥanīfah’s reasoning is that suretyship cannot attach to an obligation that is definitively determined, and the insolvent debtor does not fit that description. Those who hold the guarantee binding cite the report that in the early days of Islam the Prophet—peace and blessings be upon him—would not perform the funeral prayer over anyone who had died indebted until the debt was guaranteed on his behalf.

The majority consider suretyship for the prisoner and the absentee valid, whereas Abū Ḥanīfah does not.

With respect to the conditions of suretyship, Abū Ḥanīfah and al-Shāfiʿī stipulate that the guarantor’s right of recourse against the debtor for what he has paid depends on the debtor’s prior permission; Mālik does not require this.

According to al-Shāfiʿī it is not permissible to guarantee an unknown person or an obligation that has not yet fallen due, while Mālik and his companions accept and make binding both forms.

Regarding the financial liabilities for which ḥamālah is permissible or not, Mālik allows it for every debt firmly established in the liability except a slave’s kitābah contract, obligations that may not be deferred, and dues that accrue little by little, such as maintenance owed to wives and similar cases.