Question: If a deceased person dies and he has many debts owed to him by people, and all of them are expected [to be paid], is it valid for the heirs to divide them among themselves such that the debt owed by so-and-so is [assigned] to so-and-so, and that owed by so-and-so is [assigned] to so-and-so, and so on?
Answer: What appears is that this is permissible.
If it is said: Division (al-qismah), in meaning, is a sale, and there has come a prohibition of selling a deferred debt for a deferred debt (bayʿ al-kāliʾ bi-l-kāliʾ).
We say: As for division of cash – whether it is a debt or present [in hand] – it is not a sale; rather, it is a separation (ifrāz). Likewise is the case with all fungible things; and the division that is in the meaning of a sale is in the division of non-fungible items (al-qīmiyyāt).
Source: Min Thimār al-ʿIlm wa al-Ḥikmah vol.2