Obeyed me and kept my laws. That he made guards for guards, it teaches that Abraham to his merit removed his father's idols. My commandments. That he circumcised Isaac his son when he was 8 days old, just as God had commanded him to. My laws. These are the forbidden mixtures, as it is stated, "My rules shall you observe etc."(Leviticus 18:4) And my teachings. Both the Written Torah and the Oral Torah did Abraham keep.
How Abraham Kept the Whole Torah Before It Existed
Midrash Aggadah, Genesis 26:5