Matthew 21:9 - Wesley's Explanatory Notes

The multitudes cried, saying — Probably from a Divine impulse; for certainly most of them understood not the words they uttered. Hosanna — (Lord save us) was a solemn word in frequent use among the Jews. The meaning is, "We sing hosanna to the Son of David. Blessed is he, the Messiah, of the Lord. Save. Thou that art in the highest heavens." Our Lord restrained all public tokens of honour from the people till now, lest the envy of his enemies should interrupt his preaching before the time . But this reason now ceasing, he suffered their acclamations, that they might be a public testimony against their wickedness, who in four or five days after cried out, Crucify him, crucify him. The expressions recorded by the other evangelists are somewhat different from these: but all of them were undoubtedly used by some or others of the multitude.