Is the amount that the brother did not return due to the questioner or the brother, and is it permissible to boycott and quarrel with the brother because of this, and is he entitled to claim the remaining half?

The questioner and his brother are advised to seek judgment from knowledgeable scholars. Several points must be emphasized: It is not permissible to benefit from the brother's share except with his willing consent. In contracts, the intent and meanings are what matter, not merely the words and structures. Borrowing with usury is one of the gravest sins and is not permissible except in cases of dire necessity. The buyer's insolvency and inability to pay are excuses that permit the annulment of a sale if the seller was unaware of his insolvency. Finally, a brother should not be shunned or quarrelled with merely over a dispute concerning some rights.