Where did Paul go first when he entered a city to preach?
When entering a city to preach, Paul customarily went first to the synagogue. If the Jews there rejected the message, he then turned to the Gentiles. This pattern is described in the context as his normal practice, though the Gentiles became his chief opposition.
Les explains that every place Saul, later Paul, went, he would normally go first to the synagogue. If the Jews rejected it there, he would go out among the Gentiles. The context notes that the Gentiles became his chief opposition, and the Jews opposed Christianity left and right. This pattern reflects what the nation of Israel would do from that point on, opposing the Gospel and trying to keep it from going to the Gentiles. Les connects this to Romans 11, where God set a spiritual blindness on the nation until this day, though it will not last forever.