In Acts 11 there Peter is telling believers in Jerusalem about the wonderful vision and about the baptism of Cornelius in the chapter before (with water and Spirit). Prior to this Peter and many Jews didn't realize gentiles could be brought in.
(It's always good to reread scriptures, even such as Acts chapter 10 even when we feel we already know the passage, because not only are there the big messages (as above), but more things are usually there, too, which will help us in other ways about other questions.)