This Rewritten Bible episode relies on the Jewish liturgical tradition, which places the sacrifice of Isaac on the 15th day of Nisan, the future date of Passover. Its antiquity is confirmed by its mention in the mid-second century BCE Book of Jubilees. However, by the beginning of the second century CE the view prevailed in rabbinic circles that the sacrifice of Isaac took place on the future New Year's day, the first of Tishri. In this reinterpretation the connecting link is the blowing of the shofar (ram's horn) at New Year's day, recalling the ram substituted for Isaac as a sacrificial victim. 

Parabiblical literature, previously called pseudepigrapha or works falsely attributed to biblical personalities, is a group of writings with biblical background comprising compositions associated with a scriptural character, but with no continuous link with the sacred text. For instance the Book of Enoch, preserved fully in Ethiopic, but originally written in Aramaic as the numerous Qumran fragments reveal, is 72 chapters long. Yet Enoch figures only in five verses of Genesis (5:20-24). To the same class pertain the Testament of Levi, Amram, and Qahat, the Testaments of the Twelve Patriarchs as well as the various apocryphal works ascribed to Moses, Joshua, Samuel, Elisha, Jeremiah, Elisha, and Zedekiah from the Qumran caves and numerous other compositions collected in the two volumes of The Old Testament Pseudepigrapha by James H. Charlesworth (1983). The existence of these parabiblical writings proves that Jewish religious imagination was scripture inspired, but this literature is not part either of the Bible or of its exegesis.