In Abraham 1:2 we read:
And, finding there was greater happiness and peace and rest for me, I sought for the blessings of the fathers, and the right whereunto I should be ordained to administer the same; having been myself a follower of righteousness, desiring also to be one who possessed great knowledge, and to be a greater follower of righteousness, and to possess a greater knowledge, and to be a father of many nations, a prince of peace, and desiring to receive instructions, and to keep the commandments of God, I became a rightful heir, a High Priest, holding the right belonging to the fathers.
Where did Joseph Smith learn that Abrahan was a high priest if it is not found in the biblical account?
Jeff Lindsay notes how other texts agree with this claim such as:
If Joseph Smith wrote the Book of Abraham would we expect so many correspondences with other texts unavailable to him?