They disagreed about the worker who borrows additional funds and trades with them alongside the qirāḍ capital.
Mālik said: That is impermissible.
Al-Shāfiʿī and Abū Ḥanīfah said: It is permissible, and the profit is to be divided between them according to their stipulation. Mālik’s argument is that just as the agent may not take on a debt on behalf of the qirāḍ, so too he may not introduce borrowed money into it.

They also differed over whether the agent may sell on credit when the owner of the capital has not instructed him to do so.
Mālik said: He has no right to do so; if he does, he is liable—and al-Shāfiʿī agreed with him.
Abū Ḥanīfah held that he may.
All are nevertheless agreed that, in a qirāḍ contract, the agent may engage only in those transactions that people customarily undertake under normal circumstances. Hence, whoever regards trading on credit as outside customary practice forbids it, whereas whoever judges it customary allows it.

Mālik, al-Shāfiʿī, Abū Ḥanīfah, and al-Layth also differed about an agent who mixes his own money with the qirāḍ capital without the owner’s permission. Everyone—except Mālik—maintained that this is wrongdoing and that he is liable. Mālik said: It is not wrongdoing.

The leading jurists of the various regions are unanimous that if the agent hands the qirāḍ capital to another agent, he is liable in the event of loss; if there is profit, it is governed by the original stipulation. The one who carried out the trading then claims his stipulated share from the person to whom the capital was handed, and that person must pay him his portion out of what remains of the capital.
Al-Muzanī reports from al-Shāfiʿī that in such a case the agent is entitled only to the customary wage for someone like him, because he acted under an invalid arrangement.

The Ruling on an Invalid Qirāḍ
They agree that an invalid qirāḍ must be annulled and the capital returned to its owner so long as no trading has yet taken place. If trading has taken place, they differ over what the agent deserves for the work he was obliged to perform, and several opinions have been reported:

1. Everything is referred back to a valid qirāḍ equivalent to it. This is the narration of Ibn al-Mājishūn from Mālik, and it is the view of Mālik himself and of Ashhab.
2. Everything is referred back to the wage customarily paid to someone like him. This is the position of al-Shāfiʿī, Abū Ḥanīfah, and ʿAbd al-ʿAzīz ibn Abī Salamah among Mālik’s companions; ʿAbd al-Wahhāb also reports it as a narration from Mālik.
3. It is referred back to an equivalent qirāḍ so long as that does not exceed what had originally been stipulated; the agent is entitled only to the lesser of what was named for him or the share of an equivalent qirāḍ—unless the owner was the one who imposed the condition, in which case he is entitled to the greater of an equivalent qirāḍ or the named fraction. This opinion is derived from a narration from Mālik.
4. It is referred back to an equivalent qirāḍ for every benefit that either of the two contracting parties stipulated for himself in the capital such that neither enjoys it exclusively over the other, and to the customary wage in every benefit that one of