Joseph’s brothers Simeon and Levi suggested killing Joseph outright, but Reuben, the eldest brother, suggested that he be thrown into a pit, leaving his fate to Divine providence. The pit they chose was dry, and filled with snakes and scorpions.
Avoiding Negativity
וְהַבּוֹר רֵק אֵין בּוֹ מָיִם (בראשית לז:כד)
The pit was empty of water. Genesis 37:24

Allegorically, the pit represents the human mind and water represents the Torah. This incident thus tells us that the surest way to keep our mind free of “snakes and scorpions” – negative and destructive notions – is to ensure that it is always full of Torah-related content, for “G‑d’s Torah is wholesome, restoring the soul.”1