75. "For to Me the children of Yisrael are servants" (Vayikra 25:55). It is commanded to serve by doing many things in the Temple and out of the Temple, by all the deeds that are called 'service,' NAMELY prayer, and to strive to observe the precepts of the Torah, as everything is called 'service,' like a servant laboring to fulfill his master's needs.
76. He therefore called Yisrael 'servants,' as it is written: "For to Me the children of Yisrael are servants; they are my servants." Why are they servants? Because it is written, "whom I brought forth out of the land of Egypt" (Ibid.). It therefore says later, among the Ten Commandments, "I am Hashem your Elohim, who have brought you out of the land of Egypt" (Shemot 20:2), to serve Him as a servant does his master who saved him from death and redeemed him from all the evil things in the world.
77. Yisrael have two names before the Holy One, blessed be He. They are called 'servants,' as it is written, "they are My servants," and they are called 'children,' as it is written: "You are the children of Hashem your Elohim" (Devarim 14:1). For as long as man knows the Holy One, blessed be He, in a general way, he is called 'a servant' who does as his Master bids him, but has no permission to look into the treasures and the mysteries of His House. When he knows the Holy One, blessed be He, in a particular way, he is called 'His beloved child,' like the child who is looking at the hidden, at all the mysteries of His House.
78. Though he is called 'a son,' the firstborn son of the Holy One, blessed be He, as it is written: "Yisrael is My son, My firstborn" (Shemot 4:22), he must not exclude himself from being a servant who serves his Father in everything that glorifies His Father. So should any man be in relation to his father. A child who looks at his secrets and knows the mysteries of his house and strives after them should be a servant to his father.