The Torah, called the lamp of God, is given to us, and souls, called our lamps, are given to God. If we safeguard His lamp, He will safeguard our lamp.

Bar Kappara said: The soul and the Torah are each likened to a lamp. The soul is likened to a lamp, as it is written: “The spirit of a person is the lamp of the Lord” (Proverbs 20:27), and the Torah is likened to a lamp, as it is written: “For the mitzva is a lamp, the Torah is light” (Proverbs 6:23).

The Holy One, blessed be He, tells a person: My lamp is in your hand and your lamp is in My hand. My lamp is in your hand – that is the Torah. Your lamp is in My hand – that is the soul. If you safeguard My lamp, I will safeguard your lamp. But if you extinguish My lamp, I will extinguish your lamp. From where is this derived? It is derived from a verse, as it is written: “Only beware, and protect yourself [nafshekha] greatly” (4:9). (Devarim Rabba 4)