Now on the day he lets his sons inherit what he has, he must not treat the loved one’s son as firstborn, in place of the unloved one’s son, who is the firstborn.
Rather, he must acknowledge the firstborn, the son of the hated one, by giving him a double portion of all that he has. For he is the first of his vigor—the right of the firstborn is his.
The sons of Reuben the firstborn of Israel—he was the firstborn, but when he defiled his father’s bed, his birthright was given to the sons of Joseph son of Israel—so he is not reckoned as the firstborn in the genealogical record.
He said, “Is this why he was named Jacob—since he’s tricked me twice already? My birthright he’s taken. Look! Now he’s taken my blessing!” Then he said, “Haven’t you saved a blessing for me?”