How can a brother retract his oath of divorce regarding not riding or selling a car, after he reconciled with his brother with whom he shares ownership of the car, knowing that the oath of divorce was due to a misunderstanding between them?

The oath taken by the questioner, dear brother, is a conditional divorce (talaq (definition) mu'allaq) that cannot be revoked or undone. His wife will be divorced from him as soon as he rides the car. This is the view of the majority of scholars and the most preponderant opinion. Some scholars hold that if a person swears by divorce intending only an oath and not the divorce itself, he may undo it and must offer the expiation for an oath (kaffarat al-yamin (definition)). We must also point out that swearing by other than Allah is not permissible.