Among the textual proofs they cite is what Aḥmad and Abū Dāwūd relate from Ibn ʿUmar, who said, “I heard the Messenger of Allah ﷺ declare:

‘When you purchase and sell by ʿīnah, cling to the tails of cattle, become content with tillage, and abandon jihād, Allah will set humiliation over you and He will not lift it from you until you return to your religion.’

Aḥmad likewise transmits that the mother of Zayd ibn Arqam’s child informed ʿĀʾishah that she had sold a slave boy belonging to Zayd for eight hundred (deferred until the distribution of stipends) and then bought him back from him for six hundred dirhams. ʿĀʾishah said to her, “What an evil sale you have made and what an evil purchase! Convey to Zayd ibn Arqam that his striving alongside the Messenger of Allah ﷺ has been rendered void—unless he repents.”

It is apparent that ʿĀʾishah would not have spoken so sternly on the basis of mere personal reasoning; such a forceful reprimand can only rest upon direct instruction from the Prophet ﷺ.

Al-Shāfiʿī, however, deemed the ʿīnah sale permissible, relying on the general purport of the report collected by al-Bukhārī and Muslim from Abū Saʿīd and Abū Hurayrah: the Messenger of Allah ﷺ appointed a man over Khaybar, who later brought him some janīb (choice) dates. The Prophet ﷺ asked, “Are all the dates of Khaybar like this?” The man replied, “No, by Allah. We take one sāʿ of this for two sāʿs, and two sāʿs for three.”

The Prophet ﷺ said, “Do not do that. Sell the jumʿ (inferior dates) for dirhams, then buy janīb with the dirhams.”

The general thrust of this ḥadīth indicates that it is unobjectionable for the same person who bought the inferior dates with his dirhams to be the one who then sells the good dates, so that the dirhams return to him; the Prophet ﷺ did not forbid it. Jurists of uṣūl state, “Failing to seek further detail when several possibilities exist is treated as a ruling that applies across the board.”

As for tawarruq—purchasing a commodity on credit without intending to benefit from it, but solely in order to resell it for cash—the prevailing view among our scholars is that it is permissible. Our teacher ʿAbd al-Raḥmān al-Saʿdī also allowed it, holding that the general wording of the foregoing ḥadīth covers it and rules it lawful. He wrote in one of his books, “The purchaser is not selling it back to the very seller from whom he bought it, and the broad wording of the texts indicates …”