Seeing your brother-in-law in a dream can symbolize certain characteristics or traits within yourself that you recognize in him. It's important to also consider your real-life relationship with your brother-in-law. If you dream of arguing with your brother-in-law, it might indicate your reluctance to acknowledge or accept some of his qualities.

If your brother-in-law appears with his arm in a sling, it could suggest unhelpfulness or a lack of productivity on his part. However, if he's wearing a suit in the dream, it might signify that you are underestimating his abilities.