Abraham and Sarah watch with concern as their eight-day-old son Isaac is circumcised, according to God’s command, in this gold-and-enamel plaque made by Nicolas of Verdun in 1181 for the altar of the abbey at Klosterneuberg, near Vienna. In Genesis 17, God promises Abraham that he will be the father of many nations that will one day inherit the land of Canaan. But in return, God has a special request: “Throughout your generations, each male of yours must be circumcised when he is eight days old … And my covenant will be in your flesh as an eternal covenant” (Genesis 17:12). As William H.C. Propp shows in the accompanying article, the removal of the foreskin was much more than a badge of membership in Israelite society. Since it was usually concealed under clothing, it was a private and lasting reminder, between God and the individual, of the covenant with Abraham.