Acts 13

So when the Jews went out of the synagogue, the Gentiles begged that these words might be preached to them the next Sabbath. v.42

Read chapter 13
Notice that Paul and Barnabas are preaching in the synagogue.  That's where they'd go first to peace every time they entered a city- first  to the Jew than to the gentile- was the order during this time of the Acts period. Even than it was first to the Jews how cool is it that the gentiles are crowding around outside the synagogue and listening in.  There were many gentiles that became Jews of whom we see called proselytes in scripture but still other non-Jews wanted in without becoming circumcised and proselyte-like.  They ask here that the words might be preached to them next Sabbath- not because they wanted to hear it all over again, but that it'd be preached to THEM as a truth and promise.  Just because they heard the promise doesn't mean it's for them until specifically given.  Like if a dad tells his daughter "if you get a 4.0, I'll buy you a car."  If her friend heard this she can't expect her friend's dad to buy her a car if she gets a 4.0.  We see many blessings, curses, promises in scripture that we have to be wise to ask and see who this is to than just "read your name in to scripture whenever you want" kind of attitude.  But lets be eager to listen to God's truth no matter who specifically it might be for and to ask God to share in the blessings or make known His promises to us.