The imagery arises out of the shape of the sukkah as a protective covering. If we can sit together under the same sukkah, we will have peace.
Peace comes when we no longer hide from each other behind a wall or shout at one another across a divide. Peace comes when we sit side by side and recognise our common humanity.
Lord Jakobovits offers another perspective: “The sukkah serves as a token of peace perhaps because it is a symbol of moderation and compromise.
“It must be a temporary abode (dirat ar’ay) and yet be used like a permanent home (k’eyn taduru); its covering must be thick enough to provide more shade than sunshine inside and it should yet be loose enough to allow the stars to be seen through it; the covering material must be of plants ‘grown from the earth’ and yet be detached from the ground.
“The sukkah must be at least ten handbreadths high and yet no more than twenty cubits (approximately 3 feet and 37 feet respectively); it must accommodate a person and yet need hold only his head and the greater part of his body; it must be specially built for the festival (at least in part) and may yet be left standing from year to year. Moderation and compromise are the ingredients of peace” (Journal of a Rabbi, 1966, page 412).
The theme of unity figures not only in relation to the sukkah but in the laws and customs of the arba’ah minim. Each of the four plants is different and distinctive, yet all are needed or else the mitzvah cannot be fulfilled.
The lesson is that unless the human community, likewise composed of many different types and groups, is bound together in co-existence and cooperation, the world and its inhabitants cannot hope to survive.
Unity also comes into the sacrificial ritual for Sukkot. When the Temple was standing, seventy bullocks were offered, symbolic of what was then thought to be the seventy nations of the world. The festival taught the importance of praying for mankind as a whole with all its nations and groups.