Summary: As the Jewish army arrives at Jericho, they find the city is completely sealed off in anticipation of the attack. God instructed Joshua that the people should march around the city once every day for six days. On the seventh day seven Kohanim took seven shofarot and encircled the city seven times. At the last extended blast of the shofar the people cried out and the city walls sank into the ground.
A deeper look: The walls of Jericho were very thick and highly fortified making them impervious to enemies. Penetrating Jericho seemed an impossible task. What was the significance of marching around the city and blowing shofars to bring down the ramparts?
The Shofar blasts recall the ram sacrificed by Abraham after his command to offer Isaac as a sacrifice to God. The Midrash explains that Abraham was tested by the accusing angel, the satan who attempts to create barriers between us and God. Abraham’s faith was revealed in his ability to overcome those negative spiritual forces.
Similarly, by encircling the city over seven days (once on the first six days and seven times on the final seventh day) the Jewish people spiritually isolated the city from the rest of the idolatrous land.
Rabbi Yehudah Löwe ben Bezalel, (d. 1609, known as the Maharal MiPrague) explained the significance of the numbers six and seven. The number six represents the physical world; the six sides of a cube relate to the three dimensions of the physical world extended in both directions. The number seven represents a point beyond the physical world but nonetheless inherent to it. This is why God created the world in six days and designated Shabbat, the seventh day as a holy day on which we refrain from creative work.
These ideas are reflected in a number of our traditions. We encircle the bimah once on each of the first six days of Sukkot and seven times on the final day, Hoshana Rabbah. Similarly we encircle the bimah seven times on Simchat Torah. There is also a tradition for a bride to encircle her groom seven times under the chuppah.
Joshua succeeded in breaking the physical barriers of Jericho. Likewise, our hakafot – whether on festivals or at a wedding –symbolise breaking through the metaphysical barriers that prevent us from reaching our full potential.