I was told that one is supposed to be able to see the stars through the roof of their sukkah hut. What is the reason for this, and why have I seen sukkahs that have a very thick covering of greenery for their roofs?
On the Jewish holiday of Sukkot we build a temporary hut, called a “sukkah,” and cover it with detached branches or greenery. This covering is called sechach.
The reason for this is because, as our ancestors traversed the Sinai Desert for forty years following the exodus from Egypt and prior to their entry into the Holy Land, miraculous “clouds of glory” surrounded and hovered over them, shielding them from the dangers and discomforts of the desert. Ever since, we remember G‑d’s kindness, and reaffirm our trust in His providence, by “dwelling” in a sukkah for the duration of the Sukkot holiday.
In the words of the Torah (Leviticus 23:42–43), “For a seven-day period you shall live in booths. Every resident among the Israelites shall live in booths, in order that your [ensuing] generations should know that I had the children of Israel live in booths when I took them out of the land of Egypt. I am the L‑rd, your G‑d.”
The Talmud tells us that the sechach covering needs to be thick enough so that the shade inside the sukkah is greater than the sunlight. If the branches or greenery are not sufficient, they do not qualify as sechach.
However, the Jerusalem Talmud adds that ideally one should not place too many branches on top of the sukkah, so that one can still see the larger stars in the night sky through them.
Rabbi Joseph Teomim (d. 1792) explains that gazing at the heavens and seeing the stars reminds one of the majesty and awesomeness of the Creator. This idea is articulated by King David (Psalms 8:4–5): “When I see Your heavens, the work of Your fingers, the moon and stars that You have established, what is man that You should remember him, and the son of man that You should be mindful of him?”
In light of this, Rabbi Teomim writes, one can make a thick covering of branches over the sukkah, leaving just a small part of the covering clear in order to be able to see the stars, provided that it is not so thick that it keeps out the rain.
For a Kabbalistic take on this, see The Energy Through the Cracks of the Sukkah Hut Roof.
Please see How to Build a Sukkah from our Sukkot Minisite.