At this time the rite of circumcision was given to Abraham as "a seal of the righteousness of the faith which he had yet being uncircumcised." Romans 4:11. It was to be observed by the patriarch and his descendants as a token that they were devoted to the service of God and thus separated from idolaters, and that God accepted them as His peculiar treasure. By this rite they were pledged to fulfill, on their part, the conditions of the covenant made with Abraham. They were not to contact marriages with the heathen; for by so doing they would lose their reverence for God and His holy law; they would be tempted to engage in the sinful practices of other nations, and would be seduced into idolatry.

På denne tid fik Abraham omskærelsens anordning som "et segl på den retfærdighed af tro, han havde som uomskåren". Rom. 4, 11. Den skulle bibeholdes af patriarken og hans efterkommere som tegn på, at de var viet til Guds tjeneste og således adskilt fra afgudsdyrkerne, og at Gud antog dem som sin dyrebare ejendom. Ved denne ceremoni lovede de på deres side at opfylde betingelserne i den pagt, som var sluttet med Abraham. De skulle ikke indgå ægteskab med hedningerne, for derved ville de miste deres ærbødighed over for Gud og hans hellige lov, blive fristet til at tage del i andre folks syndige skikke og forledt til afgudsdyrkelse.