The jurists also disagreed, in this section, over a well-known offshoot: if a person is entrusted with money, then exceeds his mandate by trading with it and earns a profit, is that profit lawful for him or not?

Mālik, al-Layth, Abū Yūsuf, and a number of scholars say: once he returns the principal, the profit is lawful for him—even if he had actually usurped the capital, let alone merely held it on deposit.

Abū Ḥanīfah, Zufar, and Muḥammad ibn al-Ḥasan maintain that he must restore the principal and give the profit away in charity.

Another group holds that both the principal and the profit belong to the owner of the deposit; others say the owner may choose between taking the principal or the profit. Still others declare that every sale concluded in that business venture is invalid, and these are the scholars who require that the profit be given in charity should the custodian die.

Hence, those who give weight to the act of disposition itself assign the profit to the one who transacted, whereas those who give weight to ownership of the capital assign the profit to the owner of the money.

For this reason, when ʿUmar—may Allah be pleased with him—ordered his two sons, ʿAbd Allāh and ʿUbayd Allāh, to disburse the funds that Abū Mūsā al-Ashʿarī had advanced them from the Public Treasury, and they traded with that money and earned a profit, people said to him, “Why not treat it as a qirāḍ partnership?” He agreed, for it is reported that part of the gain went to the working partner and part to the owner of the capital, and that this was justice.