Covenant or Contract was basic to establishing cosmic order through a cosmic law and social law. Ancient Israel had two fundamental symbols, each regarded as representing the pledge of the covenant made by God with His people. These were (1) Shabbat, the Sabbath, and (2) male circumcision(cutting the foreskin off), the token of the covenant made by God with Abraham and his descendants (Gen. xvii. 11; comp. Ex. xiii. 9 and Deut. vi. 8). http://en.wikipedia.org/wiki/Jewish_symbolism