De Sacrificiis Abelis Et Caini (eng)
43
43 But he (sc. Jacob) gained all his learning from his grandfather Abraham, who gave all his property to the most wise Isaac (Gen 25:5); none of his belongings did he leave to the illegitimate children and the crooked thoughts of the concubines, but he gave insignificant things to these insignificant (heirs). For the possessions, the perfect virtues, are the property only of the perfect and legitimate (heir); the mediocre achievements are also appropriate for the imperfect ones, who only go as far as general propaedeutic knowledge, towards which Hagar and Keturah lead; Hagar, "sojourning in a foreign land"; Keturah, "the fragrant one."