Hoshanot

The concept known as “Hoshanot,” has its origin in the prophets. It is connected to the later prophets known as Chagai, Zechariah, and Malachi.
This included a marching around the outer altar in the Beit Hamikdash one time each day of Succot. They circled the Mizbeach seven times on the seventh day, which is the origin of the name, “Hoshana Raba,” or, the numerous Hoshanot.
The taking of the Arava, the willow, on the seventh day and striking a batch of five of them on the seventh day, is known as “Halacha LeMoshe MiSinai,” where it’s origins were from Mount Sinai.
There is no connection between the two willow branches that are part of our Lulav and Etrog quartet, and this ceremony of the seventh day.
The willow has no taste and no smell and represents the Jew who is lacking in Torah and good deeds. The symbolism is that we are beating the negative traits that still need correcting in our Teshuva process.
There is another underlying message here. The willow tend to be found near bodies of water. This time of year the focus is on rain that brings sustenance for the entire year. We pray for rain on Shemini Atzeret, the eighth day of Succot. The beating of the willows is somehow meant to create more merit for a good rainy season and sustenance to all.
There are also many messages on a deeper, more metaphysical level, regarding the entire ceremony of Hoshanot. We should take this ceremony very seriously, and pray for the benefits that come with it.