723 – Ibn ʿUmar (may Allah be pleased with them both) reported that the Prophet ﷺ “forbade selling kāliʾ for kāliʾ—that is, exchanging one debt for another.” It was transmitted by Isḥāq and al-Bazzār with a weak chain of narrators.⦗1⦘

Degree of the hadith:
The report is weak. Nonetheless, it falls under the sound hadith that prohibits sales involving gharar (excessive uncertainty). Its weakness stems from the fact that Mūsā ibn ʿUbayda alone related it from Nāfiʿ, and he is a weak narrator. Aḥmad said, “It is impermissible to relate from Mūsā ibn ʿUbayda, and I know of no one else who narrates this hadith.” Imams al-Shāfiʿī and al-Bayhaqī likewise graded it weak. Al-Dhahabī remarked, “The scholars declared him weak,” and Ibn Ḥajar also said, “Weak.”

Even though its chain is weak, the Muslim community has nevertheless accepted the hadith, as Ibn ʿArafah observed. Such acceptance by the leading scholars removes the need to scrutinize its isnād further. Moreover, the jurists have reached consensus that exchanging one debt for another is impermissible. Imām Aḥmad stated, “No sound hadith on this issue exists, but people unanimously agree that a debt may not be sold for a debt.”

Vocabulary of the hadith:
– kāliʾ bi-l-kāliʾ: pronounced with an open kāf, a kasra on the lām, and a hamza written on a yāʾ. It derives from kalaʾa al-dayn—when payment of a debt is deferred. Kalaʾahu can also mean “he forgot it.” In al-Nihāya it is glossed as “al-nasīʾa for al-nasīʾa,” and al-nasīʾa (deferral) denotes postponement.