In biblical times a contract or agreement of friendship between persons or nations was completed in a ceremony in which the two parties walked between the two halves of an animal sacrifice (Gen. 15:9-11). In the biblical covenants between God and Israel, a sign accompanied each renewal of the contract. When God made a covenant with Noah after the flood, He set the rainbow as a sign that “the waters shall no more become a flood to destroy all flesh” (Gen. 9:13-15). In the covenant God made with Abraham, giving to him and to his children the land of Canaan for “an everlasting possession,” circumcision was the sign (Gen. 17:10). When the Lord renewed the covenant with the Children of Israel at Sinai, His sign was the Sabbath (Exod. 31:13). In the Bible, the Torah itself is called “the Book of the Covenant,” the stone tablets with the Ten Commandments “the tablets of the covenant,” a reminder that Israel’s part of the contract was faithfulness to God and righteous behavior toward men.