Contradiction with Genesis 4:19
Lamech took two wives, contradicting the restriction in Leviticus 18:18 against taking a sister to her as a wife.
Genesis 4:19: And Lamech took unto him two wives: the name of the one [was] Adah, and the name of the other Zillah.
Contradiction with 1 Samuel 1:1-2
Elkanah had two wives, demonstrating a situation where having more than one wife was practiced.
1 Samuel 1:1-2: Now there was a certain man of Ramathaimzophim, of mount Ephraim, and his name [was] Elkanah, the son of Jeroham, the son of Elihu, the son of Tohu, the son of Zuph, an Ephrathite:
Paradox #1
This verse might seem to conflict with the practices of some biblical figures who had multiple wives or concubines, which were sometimes depicted without condemnation. This could be seen as inconsistent with rules that prohibit marrying certain relatives simultaneously.