It is possible that Paul himself circumcised Timothy, but it is more likely that he had someone else circumcise Timothy.
# because of the Jews that were in those places
"because of the Jews living in the areas where Paul and Timothy would be traveling"
# for they all knew that his father was a Greek
Since Greek men did not have their sons circumcised, the Jews would have known Timothy was not circumcised, and they would have rejected Paul and Timothy before hearing their message about Christ. (See: [[rc://en/ta/man/translate/figs-explicit]])