In the accounts of the four canonical Gospels, Jesus' triumphal entry into Jerusalem takes place about a week before his Resurrection. According to the Gospels, Jesus rode a donkey into Jerusalem, and the celebrating people there lay down their cloaks in front of him, and also lay down small branches of trees. The people sang part of Psalms 118: 25–26 – ... Blessed is He who comes in the name of the Lord. We bless you from the house of the Lord.
The symbolism of the donkey may refer to the Eastern tradition that it is an animal of peace, versus the horse, which is the animal of war. Therefore, a king came riding upon a horse when he was bent on war and rode upon a donkey when he wanted to point out he was coming in peace. Therefore, Jesus' entry to Jerusalem symbolized his entry as the Prince of Peace, not as a war-waging king.
In many lands in the ancient Near East, it was customary to cover in some way the path of someone thought worthy of the highest honour. The Hebrew Bible (II Kings 9:13) reports that Jehu, son of Jehoshaphat, was treated this way. Both the Synoptic Gospels and the Gospel of John report that people gave Jesus this form of honour. However, in the synoptics [i.e. the first 3 gospel accounts], they are only reported as laying their garments and cut rushes on the street, whereas John more specifically mentions palm fronds. The palm branch was a symbol of triumph and victory in Jewish tradition, and is treated in other parts of the Bible as such (e.g., Leviticus 23:40 and Revelation 7:9). Because of this, the scene of the crowd greeting Jesus by waving palms and carpeting his path with them and their cloaks has become symbolic and important.
In the 16th and 17th centuries, Palm Sunday was marked by the burning of Jack-'o'-Lent figures. This was a straw effigy which would be stoned and abused. Its burning on Palm Sunday was often supposed to be a kind of revenge on Judas Iscariot, who had betrayed Christ. It could also have represented the hated figure of Winter whose destruction prepares the way for Spring.
On Palm Sunday with Roman Catholic, Anglican and Lutheran congregations, palm fronds or foliage leaves/branches are blessed with holy water outside the church building. A procession also takes place. It may include the normal liturgical procession of clergy and acolytes, the parish choir, or the entire congregation.