Education
Chp. 17: Hashem asks Avram to become perfect with the mitzvah of circumcision. This would be an everlasting covenant between G-d and Avram's children forever. Hashem then changes his name to Avraham and Sawri to Sawra. Hashem promises him the land and a son from Sawra whom he will name Yitzhok. Hashem also promises him that Yishmael will be successful. At age 99, he circumcises himself and all the male members of his household, to include Yishmael who was 13 years old.