There is some debate as to the precise meaning of this phrase. Most likely it refers to the manner of life that was promulgated by the Pharisees.1 Reflecting on and interpreting the Old Testament, various additional laws and practices were developed over time, eventually codified in writings such as the Mishnah, the Tosephta and the Jerusalem and Babylonian Talmuds.2
14 And I was advancing in Judaism beyond many of my own age among my people, so extremely zealous was I for the traditions of my fathers.