What is the Sharia ruling on dealing with the fiancée's brother who procrastinates in completing the marriage despite prior agreement and humiliates his sister, and is delaying the marriage after he sold his car for her sake considered a concession that displeases Allah?

The girl's guardian must approve her marriage to a suitable suitor who proposes to her, and her marriage should be expedited. It is not permissible to delay her marriage without a valid reason. The guardian must also fear Allah concerning those under his guardianship, for it is a trust, and he will be held accountable for it on the Day of Judgment. The engaged couple should fear Allah and not overstep His bounds, as they remain strangers to each other until the marriage contract is concluded. The questioner should be gentle with the guardian and send someone influential to him to expedite the matter.