The word is taken from Ps. 118: 25, one of the Psalms of the Hallel. The chanting of this psalm was connected at the Feast of Tabernacles with the waving of palm branches; hence the use of the word by the multitudes at our Lord's triumphal entry into Jerusalem (Matt. 21: 9, 15; Mark 11: 9, 10; John 12: 13).