Musar על סנהדרין 198:10

Chazal have said (Sanhedrin 99b): “All who study Torah for its own sake make peace in the celestial and terrestrial retinues, viz. (Isaiah 27:5): ‘Or if he but take hold of My stronghold [Torah], he shall make peace for Me [1]; he shall make peace for Me [2].’ Rav said: ‘It is as if he would build the celestial palace and the terrestrial palace, viz. (Ibid. 51:16): “And I have placed My words in your mouth … to plant the heavens and to lay the foundations of the earth.”’”