To salute Jesus.
King of the Jews!’”
καὶ ἤρξαντο ἀσπάζεσθαι αὐτόν Χαῖρε, Βασιλεῦ τῶν Ἰουδαίων·
This is almost word for word in Matthew, chapter 27:29, but not in Luke. In John, chapter 19:3, there is something similar. Mark said that these Roman soldiers began to salute Jesus (καὶ ἤρξαντο ἀσπάζεσθαι αὐτόν), as they mocked him, saying, “Hail (Χαῖρε)! King of the Jews (Βασιλεῦ τῶν Ἰουδαίων)!” Clearly, the title “King of the Jews” had become popular for addressing Jesus in a teasing way.