Acts 11:2

So when Peter went up to Jerusalem, those of the circumcision [certain Jewish believers who followed the Law] took issue with him [for violating Jewish customs],

Acts 10:45

All the circumcised believers who came with Peter were amazed, because the gift of the Holy Spirit had been poured out even on the Gentiles.

Acts 10:9

The next day, as they were on their way and were approaching the city, Peter went up on the roof of the house about the sixth hour (noon) to pray,

Acts 15:1

Some men came down from Judea and began teaching the brothers, “Unless you are circumcised in accordance with the custom of Moses, you cannot be saved.”

Acts 15:5

But some from the sect of the Pharisees who had believed [in Jesus as the Messiah] stood up and said, “It is necessary to circumcise the Gentile converts and to direct them to observe the Law of Moses.”

Acts 21:20-23

And when they heard it, they began glorifying and praising God; and they said to him, “You see, brother, how many thousands of believers there are among the Jews, and they are all enthusiastic supporters of the Law [of Moses].

Galatians 2:12-14

Before certain men came from James, he used to eat [his meals] with the Gentiles; but when the men [from Jerusalem] arrived, he began to withdraw and separate himself [from the Gentile believers], because he was afraid of those from the circumcision.

Treasury of Scripture Knowledge

Summary

And when Peter was come up to Jerusalem, they that were of the circumcision contended with him,

General references

Bible References

They

Acts 10:9
The next day, as they were on their way and were approaching the city, Peter went up on the roof of the house about the sixth hour (noon) to pray,
Acts 15:1
Some men came down from Judea and began teaching the brothers, “Unless you are circumcised in accordance with the custom of Moses, you cannot be saved.”
Acts 21:20
And when they heard it, they began glorifying and praising God; and they said to him, “You see, brother, how many thousands of believers there are among the Jews, and they are all enthusiastic supporters of the Law [of Moses].
Galatians 2:12
Before certain men came from James, he used to eat [his meals] with the Gentiles; but when the men [from Jerusalem] arrived, he began to withdraw and separate himself [from the Gentile believers], because he was afraid of those from the circumcision.

General references

1 Samuel 17:29
But David said, “What have I done now? Was it not just a [harmless] question?”