YeHoVaH told Abraham to no longer call his wife Sarai, but Sarah. Sarai first heard her new name called by her husband Abraham, not by YeHoVaH.  It is clear according to YeHoVaH’s intent, that in order for the Covenant YeHoVaH made with Abraham to come to pass, Sarah had to comply and come in agreement with it.  Although Abraham felt it was impossible for him and Sarah to bear children together, he knew it was not impossible for the Most High Elohim to produce a child with them!After the conversation with YeHoVaH, Abraham took Ishmael and all the men of his house and circumcised them as YeHoVaH had commanded.  This Command of Circumcision brought all of the men in Abraham’s house into and under the Covenant YeHoVaH made with Abraham.  Abraham was 99, when he was circumcised in the flesh of his foreskin.  Our circumcision is based on the Covenant of Abraham; not a Mosaic Covenant or Covenant made with the Jews.