During Paul's second missionary journey, he meets Timothy and wants to take him along on the rest of his journey. The Bible makes a special point about Timothy being circumcised to avoid offending the Jews:
Acts 16:1-3 (NASB)
1 Paul came also to Derbe and to Lystra. And a disciple was there, named Timothy, the son of a Jewish woman who was a believer, but his father was a Greek, 2 and he was well spoken of by the brethren who were in Lystra and Iconium. 3 Paul wanted this man to go with him; and he took him and circumcised him because of the Jews who were in those parts, for they all knew that his father was a Greek.
I understand that the Jews who knew Timothy would assume that he wasn't circumcised because his father wasn't Jewish. How would they know that he had been circumcised? Would Paul and Timothy just announce it? Would the Jews insist on verifying it?