Contradiction with Genesis 35:22
This verse indicates Reuben was Jacob's eldest son, but does not explicitly discuss inheritance rights, while 1 Chronicles 5:3 acknowledges him as firstborn but implies he lost his birthright due to actions mentioned later in the text.
Genesis 35:22: And it came to pass, when Israel dwelt in that land, that Reuben went and lay with Bilhah his father's concubine: and Israel heard [it]. Now the sons of Jacob were twelve:
Contradiction with Genesis 49:3-4
These verses discuss Reuben’s unstable character and why he does not excel, supporting the notion he lost certain rights as firstborn, contrasting with the simple label of "firstborn" in 1 Chronicles 5:3.
Genesis 49:3-4: Reuben, thou [art] my firstborn, my might, and the beginning of my strength, the excellency of dignity, and the excellency of power:
Contradiction with 1 Chronicles 5:1
This verse explicitly states that although Reuben was the firstborn, his birthright was given to Joseph's sons because of Reuben’s transgression, directly addressing a contradiction with the simple listing of Reuben as firstborn in 1 Chronicles 5:3.
1 Chronicles 5:1: Now the sons of Reuben the firstborn of Israel, (for he [was] the firstborn; but, forasmuch as he defiled his father's bed, his birthright was given unto the sons of Joseph the son of Israel: and the genealogy is not to be reckoned after the birthright.