Is the money the husband took from his father as aid for marriage on the basis of a debt, and the father enjoined it to be put into the mosque, considered a will for his deceased father or a debt that must be repaid to the heirs, especially since the husband's brothers are demanding that he repay this debt as a will from the father?

The father-in-law's instruction to allocate a debt to the mosque is a bequest (wasiyya), as is the father's instruction to his children to give a thousand dinars from his wealth as charity on his behalf. The fundamental principle is that both bequests must be fulfilled. If one-third of the inheritance is sufficient for both, then both must be executed. If one-third of the inheritance is insufficient for both, and the heirs do not permit it, then the one-third is divided between the two bequests, with each taking its proportionate share of the one-third. Therefore, the husband's debt to the mosque is obligatory, and the children's charity of a thousand dinars on behalf of their father is obligatory. If one-third of the inheritance is not sufficient for both bequests, then the one-third is divided between them proportionally. Whatever remains of the husband's debt to his father after this is included in the total inheritance and divided among the heirs.