The first reason that Jesus aroused opposition was because of the manner of his entry into Jerusalem at the beginning of the final week of his ministry. He entered the holy city mounted on a donkey, amid shouts of “Hosanna! Blessed is the coming kingdom of our ancestor David!” (Mark 11:1-10; here vv. 9-10, NRSV, modified).
Entering the city in this way deliberately mimicked Solomon, David’s son, who one thousand years earlier rode the royal mule as part of his declaration of kingship (1 Kings 1:32-40). Such an entry also answered the ancient prophecy of the anticipated humble king (Zechariah 9:9).
Not only did Jesus’ act recall hopes of a coming son of David, but the crowd’s response reflected the same popular interpretation of it. Their Hosannas, as an allusion to Psalm 118, were a pronouncement that this one who comes to the temple “in the name of the Lord” is none other than David, the one destined to be Israel’s king and ruler (see Psalm 118:19-27, according to the Aramaic paraphrase).
Such an event suggested in unmistakable terms that Israel’s king was Jesus, not Caesar. Thus, from the very moment of entry into Jerusalem, Jesus was set on a collision course with Roman authority.
Evans, C & Wright, N.T. (2008). Jesus, the Final Days: What Really Happened [ebook], Westminster John Knox, Location 87-95