Jesus is an expert at fulfilling prophecies—whether or not he has a say in the matter. It's kind of uncanny, actually. But why is Matthew so focused on it? Well, Matthew's prime audience was the Jewish community, so he needed to use the many prophecies of the Hebrew Bible to convince his readers that Jesus was the Messiah. Unfortunately, Matthew doesn't have a works cited for us, but back in the day, everyone would have known exactly what he was referring to. And biblical scholars have pored over scripture for centuries so we can know, too.