Genesis 11:29, 20:11-12 [11:29] And Abram and Nahor took them wives: the name of Abram's wife was Sarai; and the name of Nahor's wife, Milcah, the daughter of Haran, the father of Milcah, and the father of Iscah. [20:11] And Abraham said, Because I thought, Surely the fear of God is not in this place; and they will slay me for my wife's sake. [20:12] And yet indeed she is my sister; she is the daughter of my father, but not the daughter of my mother ; and she became my wife. (Abraham's wife Sarah was his half sister)
Genesis 24:4, 15, 67 [24:4] But thou shalt go unto my country, and to my kindred , and take a wife unto my son Isaac. [24:15] And it came to pass, before he had done speaking, that, behold, Rebekah came out, who was born to Bethuel, son of Milcah, the wife of Nahor, Abraham's brother, with her pitcher upon her shoulder. [24:67] And Isaac brought her into his mother Sarah's tent, and took Rebekah, and she became his wife; and he loved her: and Isaac was comforted after his mother's death. (Isaac married his second cousin Rebekah)
Genesis 29:21-23 [29:21] And Jacob said unto Laban, Give me my wife, for my days are fulfilled, that I may go in unto her. [29:22] And Laban gathered together all the men of the place, and made a feast. [29:23] And it came to pass in the evening, that he took Leah his daughter, and brought her to him; and he went in unto her. (Jacob married his cousin Leah)
Genesis 29:28-30 [29:28] And Jacob did so, and fulfilled her week: and he gave him Rachel his daughter to wife also. [29:29] And Laban gave to Rachel his daughter Bilhah his handmaid to be her maid. [29:30] And he went in also unto Rachel, and he loved also Rachel more than Leah, and served with him yet seven other years. (Jacob married his cousin Rachel)
Exodus 6:20 And Amram took him Jochebed his father's sister to wife ; and she bare him Aaron and Moses: and the years of the life of Amram were an hundred and thirty and seven years. (Amram married his aunt.)