Commentators note that there is no reference in the Old Testament to any incident in the life of the Patriarch to which this redemption can refer specially, but that there is a tradition that he, at some time, was threatened with the fire of a burning furnace. In the Book of Abraham, Pearl of Great Price, I think, we find the story of the redemption of Abraham to which Isaiah (29:22) and Nephi here refer.
Abraham was a native of Ur of the Chaldees. ( Gen. 11:28)
According to the Book of Abraham, the Egyptians had an altar and a religious establishment there, just as, for instance, Americans in our day have churches and congregations in some of the principal cities of the world, such as London, Paris, etc. The paternal relatives of Abraham, it seems, had turned away from the religion of their ancestors and were worshiping pagan idols, and especially the divinities of Egypt. They even delighted in the sacrifice of children.
Then a time came, when the priests of Pharaoh seized Abraham, intending to take his life on the altar. But when he lifted up his voice to God, the "Angel of his (God's) Presence" appeared, unloosened the bands of the intended victim, promised him the Priesthood, and declared that: "Through thy ministry my name shall be known in the earth forever, for I am thy God." Then, "the Lord broke down the altar of Elkenah and of the gods of the land, and utterly destroyed them, and smote the priest that he died." The country must have been visited by some unusual calamity, for the record says: "There was great mourning in Chaldea, and also at the court of Pharaoh." (Book of Abraham 1:5-20)
It was thus that God redeemed Abraham by almighty power and taught him one of the lessons that enabled him to become the "father of all that believe." (Rom. 4:11)