The Feast of Tabernacles: Customs Observed At: Bearing Branches of Palms
Source: TTT
Leviticus 23:40
On the first day you are to gather the fruit of majestic trees, the branches of palm trees, and the boughs of leafy trees and of willows of the brook. And you are to rejoice before the LORD your God for seven days.
Revelation 7:9
After this I looked and saw a multitude too large to count, from every nation and tribe and people and tongue, standing before the throne and before the Lamb. They were wearing white robes and holding palm branches in their hands.