Abraham stands at the headwaters of the Jewish story, and the Talmud gathers around him a flood of legends — score upon score of traditions that stretch far beyond what the Book of Genesis records. The sages of the Talmud understood something that historians sometimes miss: a people is shaped not only by what its ancestors actually did, but by what their descendants imagine them to have done.
The rabbis piled midrash upon midrash about Abraham's kindness, his debates with idolaters, his stargazing, his bargaining with God over Sodom (Genesis 18:23-33). These stories gave emunah, faith, a face and a voice. The child who hears that Abraham smashed his father's idols learns courage before he can spell it.
As the 1901 anthology Hebraic Literature observes, "Races and nations often draw more inspiration from what they fancy about their ancestry than from what they know; their fables therefore are often more illuminative than the facts." The Jewish legends about Abraham are not decoration on the biblical narrative — they are the soul the narrative grew into.