Contradiction with Genesis 20:12
Abraham indicates that Sarah is his sister, although Leviticus 18:6 delineates prohibitions on uncovering kin's nakedness, which can be viewed as an indirect reference to family relations not to be dishonored.
Genesis 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.
Contradiction with Genesis 29:21-23
Jacob marries Leah through a deceptive scheme ruling out transparency, contrasting Leviticus 18:6’s call for honor within family relations.
Genesis 29:21-23: And Jacob said unto Laban, Give [me] my wife, for my days are fulfilled, that I may go in unto her.
Contradiction with 2 Samuel 13:12-14
The story of Amnon and Tamar involves violation and dishonor within family lines, conflicting with the kinship respect underscored in Leviticus 18:6.
2 Samuel 13:12-14: And she answered him, Nay, my brother, do not force me; for no such thing ought to be done in Israel: do not thou this folly. [force...: Heb. humble me] [no such...: Heb. it ought not so to be done]
Contradiction with Exodus 6:20
Amram marries his father's sister Jochebed, portraying a familial bond that Leviticus 18:6 would discourage by its prohibitions against uncovering a relative’s nakedness.
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.
Contradiction with Genesis 38:16-18
Judah has relations with Tamar, his daughter-in-law, which presents complexities around familial relationships that Leviticus 18:6 aims to regulate with definitive bounds.
Genesis 38:16-18: And he turned unto her by the way, and said, Go to, I pray thee, let me come in unto thee; (for he knew not that she [was] his daughter in law.) And she said, What wilt thou give me, that thou mayest come in unto me?
Paradox #1
Leviticus 18:6 could be seen as morally inconsistent because the Bible elsewhere records instances of close family relationships being accepted or important, such as the marriages of cousins. Some might see this as a contradiction in applying rules about relationships.