Here the author begins to tell about how Herod had executed John the Baptist. These events occur some time before the event in the previous verses. (See: [[rc://en/ta/man/translate/figs-events]])
It says that Herod did these things because he ordered others to do them for him. Alternate translation: "Herod ordered his soldiers to arrest and bind John the Baptist and put him in prison" (See: [[rc://en/ta/man/translate/figs-metonymy]])