Is the husband's oath of divorce, "If you let any of your family in, then you are not bound to me," considered a divorce, given that four years have passed without the wife letting any of her family in, in compliance with the oath, and is it permissible for him to retract this oath and allow her family into the home?

The reason for this oath is the interference of the wife's family in the affairs of the husband and his wife. Therefore, the divorce does not occur if the cause sworn upon ceases to exist, meaning if the interference of the wife's family in the marital home affairs stops. This is what the Malikis call "bisat al-yamin (definition)" (the context of the oath); it is the reason that prompted the oath.

If the swearer did not have an intention or if it was not clearly defined, then the oath is specified and restricted by its context (bisat), which is the reason that prompted the oath. An example of this is someone who swore not to buy something due to the crowd, then the crowd dispersed and he bought it; he does not break his oath because the reason that prompted him to swear has ceased to exist.

If the swearer had no intention, one looks at the context of his situation and what prompted him to swear. The point is that intention affects the oath, specifying or generalizing it. The reason stands in place of intention when it is absent, indicating it and having the same effect as intention.