The Book of Formation of the Patriarch Abraham

...thus consecrating and devoting myself, so that I am most ready to face the greatest dangers of poverty, pain, and the infamy of disgrace in place of the greatest wealth, pleasures, and honors for the sake of this cause. Farewell, most revered fathers, and attend with your whole heart to the secret doctrines of father Abraham Postel refers here to the Sefer Yetzirah or "Book of Formation," an ancient mystical text he attributed to the patriarch Abraham. The first day of July, 1552.