Laban was the brother of Jacob’s mother, Rebekah (Genesis 29:10). This relationship would have made Laban’s daughter Rachel-the woman whom Jacob wanted to marry-Jacob’s first cousin. Sometimes the term brother was used loosely in Bible times to refer to any male relative such as a nephew or an uncle (see note on Genesis 14:16). So Rachel may have been a distant relative of Jacob.
Marriage among distant relatives from the same tribe or bloodline was common in the Old Testament times. Abraham sought a wife for his son Isaac from among his kinsmen in Mesopotamia (see note on Genesis 24:4).
GENESIS 29:19- It is better that I [Laban] give her [Rachel] to thee [Jacob], than that I should give her to another man.