The crowds that went ahead of him and those that followed shouted, “Hosanna to the Son of David!” “Blessed is he who comes in the name of the Lord!” “Hosanna in the highest heaven!”  Matthew 21:9

Hosanna is a word that was used to praise God. Kind of like saying, “Yay, God!” The people and especially the little children yelled out Hosanna when Jesus rode into town on a donkey on Palm Sunday.