Jan van Reeth argues that the Book of Jubilees had great influence on the formation of Islam. In the Book of Jubilees there is the very same concept of revelation as in Islam: God's words and commandments are eternally written on celestial tablets. An angel reveals their content to a prophet (2, 1; 32, 21 f.). Abraham's role in the Book of Jubilees corresponds to Abraham's role in the Quran in more than one way. The interpretation of biblical figures as prophets is also rooted in the Book of Jubilees. Also numerology, the emphasis on angels, and the symbolism of anniversaries found their way into Islam, such as the fact that many important events in the prophet's biography as presented by Ibn Ishaq happen on the same date.