Matthew 21:9
And the crowds that walked ahead and followed behind Him shouted, "Hosanna to the son of David. [Note: The Syriac word 'Hosanna' originally meant 'save now' but came to be used as an expression of welcome, praise, blessing or acclamation]. May He, who comes in the name [i.e., by the authority] of the Lord, be blessed. Hosanna in the highest [i.e., may this blessing reach to the highest heaven]."
Matthew 21:15
But when the leading priests and the experts in the law of Moses saw the wonderful things [i.e., miracles] He was performing and [heard] the children shouting in the Temple, "Hosanna to the son of David," [See note at verse 9], they were filled with anger [i.e., over the acclaim being given to Jesus].