What is the ruling of Islamic law regarding a disagreement between spouses concerning the method of repaying the husband's debt to his wife: should it be in gold (by the weight of the gold sold) or in money (by the value of the money received)?

The ruling on this matter depends on the type of agreement between the spouses. If the agreement was that she would lend you her gold for you to sell it and benefit from its price, then you are obligated to return the equivalent weight of gold. However, if the agreement was that she would sell her gold and lend you its price, then you are obligated to return the amount you took from her.

In case of a dispute between the creditor and the debtor, the statement of the one who has evidence or witnesses is accepted. If there is none, then the statement of the debtor with his oath is accepted. The proof for this is the saying of the Prophet, peace be upon him: "The burden of proof is on the claimant, and the oath is on the defendant." Additionally, "Al-Mawsu'ah al-Fiqhiyyah," "Al-Manthur fi al-Qawa'id," and "Al-Sharh al-Mumti'" affirm that the statement of the debtor with his oath is accepted regarding the description and amount, because the original principle is the acquittal of his liability from any excess.

To prevent such disputes, Islamic law encourages documenting debts, as stated in the Almighty's words: "O you who have believed, when you contract a debt for a specified term, write it down" and "And do not be [too] weary to write it, whether it is small or large, for its [specified] term. That is more just in the sight of Allah and stronger as evidence and more likely to prevent doubt."

In addition to the legal and judicial ruling, the relationship between spouses should be based on affection, mercy, grace, and kindness, and it should be greater than being marred by disputes over worldly matters, as Allah Almighty said: "And do not forget graciousness between you."