A brother-in-law is the brother of one’s spouse. Biblically a brother-in-law could represent the same thing as a brother, but under the law.
Positive: Dreaming of a brother-in-law could represent the man himself, a minister in another church, or someone who has similar qualities to him.
Negative: Seeing a brother in law in a dream could represent religiousness or adversity.
(Esther 7:6; Exodus 18:17; Galatians 3:5; Romans 4:13-15; 1 Timothy 5:1).