Where did Peter and the 11 preach that circumcision was necessary for salvation?

In one of my posts I mentioned the following,

Peter and the 11 preached that physical circumcision was necessary for salvation —God clearly stated that He wanted nothing to do with a physically-uncircumcised Jew in Israel's program, for physical circumcision was the sign of the Abrahamic Covenant, Gen 17:7-14.

The following question/statement came in as comment on the post,

Where did Peter and the 11 preach that circumcision was necessary for salvation? Read Acts 15:4-20 and you won't find anything regarding this. Nothing here from Peter and the 11 says one must be circumcised.

I thought it a great opportunity to write a reply to provide clarity.

MY REPLY:

Of course there is nothing in this passage. This passage concerns the Jerusalem council meeting where decisions were made on how to manage the new Gentile converts that were in the assemblies. Some concessions were made to limit the friction between the law-abiding Jewish members and the ‘free-range’ Gentiles. So, this passage has nothing to do with the requirements of the members of the Little Flock.

However, to answer your question, just read the scripture passage quoted in the paragraph you are referring to and you will see the absolute strictness of this covenant requirement. If any males were not circumcised, they were cut off from the blessings and inheritance of God for Israel. This requirement has never changed in all of time, and the 12 were still abiding by this. Thus, it speaks to reason that Peter preached a circumcision gospel for salvation. If anyone heard this gospel and declined circumcision…they were cut off.