Is the statement "If you do not get me engaged to this girl, then your niece is forbidden to me" considered a divorce, given that it was said in a state of extreme anger with the intention of compelling the mother to agree to a second marriage, and the wife was not present, and divorce was not intended?

The statement by the questioner to his mother: "If you do not propose to this girl for me, then your brother's daughter is forbidden to me," intending to compel her to help him marry the girl, and not intending divorce, is considered an oath and not a divorce.

His breaking of this oath is tied to the fulfillment of its condition, which is the mother proposing to the girl: - If the mother proposes, he does not break the oath. - If she does not propose, he breaks the oath, and an expiation for an oath becomes obligatory upon him (feeding ten poor persons or clothing them, or emancipating a slave; if he cannot find these, then fasting for three days).

As for considering the mother's contact with the girl's family and her agreement after the proposal as supporting her son: - This goes back to the son's intention at the time of the oath: If he intended her support before the proposal, the oath is broken. If he intended her support at any time, even after the proposal, he does not break the oath. - It is preferable for him to perform the expiation for an oath in all cases, as it is more cautious and clears his conscience.