The seventh day of Sukkot is called Hoshanah Rabbah (“Great Salvation”).
Hoshanah is a name of a prayer said during the Sukkot holiday. The prayer includes the phrase “Hoshi’a Na”, save please, hence its name. On Hoshanah Rabbah the Hoshanah is said many times, hence the name Hoshanah Rabbah – the Great Hoshanah.
During Hoshanah Rabbah it is customary to circle the synahgogue seven times, holding The Four Species, and say the Hoshanah. This custom originates in a temple ritual of circling the altar.
During the morning prayers it is also customary to take a bundle of five willow branches and beat them against the ground five times.