How can you believe every word of the Bible when there are so many contradictions?
50. Marriage or cohabitation with a sister denounced
Deut 27:22/ Lev 20:17
Abraham married his sister and God blessed the union
Gen 20:11,12/ Gen 17:16
51. A man may marry his brother's widow
A man may not marry his brother's widow
First, to be exact, Abraham married his half-sister. Second, Abraham did this WAY before God instituted laws against incest. God did not prohibit marriage between close relatives until Moses's time, over 400 years after Abraham. Remember, Abraham lived just 300 years after the flood, and God was replenishing the earth's population, not unlike when he created Adam and Eve. Therefore, the same rules applied. No contradiction.
As for the second “contradiction”, Deuteronomy says marrying a brother's widow is not wrong. Leviticus says marrying a brother's wife (not widow) is wrong. In one case, the brother is dead; in the other the brother is alive. That's quite a difference, wouldn't you say? No contradiction. Note that the Leviticus law is what John the Baptist threw in Herod's face in Mark 6:17, 18.
This is a good example of why I want people to write their own ideas instead of googling them. Save yourself some embarrassment; at least read what you send, and confirm that quotes are accurate.