"For thisreasonMoseshas givenyou circumcision(not becauseit is from Moses,but from the fathers),and on [the] Sabbathyou circumcisea man.
Then Abrahamcircumcisedhis sonIsaacwhen he was eightdaysold,as Godhad commandedhim.
On the eighthdaythe fleshof his foreskinshall be circumcised.
"And He gavehim the covenantof circumcision;and so[Abraham] became the fatherof Isaac,and circumcisedhim on the eighthday;and Isaac[became the father of] Jacob,and Jacob[of] the twelvepatriarchs.
What I am sayingis this:the Law,which camefour hundredand thirtyyearslater,does not invalidatea covenantpreviously ratifiedby God,soas to nullifythe promise.