Acts 16:3
"Him would Paul have to go forth with him; and took and circumcised him because of the Jews which were in those quarters: for they knew all that his father was a Greek."
Cross References (ranked by relevance)
But neither Titus, who was with me, being a Greek, was compelled to be circumcised:
And unto the Jews I became as a Jew, that I might gain the Jews; to them that are under the law, as under the law, that I might gain them that are under the law;
For in Jesus Christ neither circumcision availeth any thing, nor uncircumcision; but faith which worketh by love.
Circumcision is nothing, and uncircumcision is nothing, but the keeping of the commandments of God.
And Paul chose Silas, and departed, being recommended by the brethren unto the grace of God.
But that we write unto them, that they abstain from pollutions of idols, and from fornication, and from things strangled, and from blood.
(For he that wrought effectually in Peter to the apostleship of the circumcision, the same was mighty in me toward the Gentiles:)
And Barnabas determined to take with them John, whose surname was Mark.