זוהר בראשית — דף קפז ע”א

“He did not create it a waste, He formed it to be inhabited”: the Holy One, blessed be He, made man as he should be. On “if You make his soul an offering for guilt, he shall see offspring,” the Zohar explains that this is the soul that wishes to be repaired and is destined to enter the seed with which a person engaged in being fruitful and multiplying. Even one who engages in Torah day and night, if his source stands idle, has no place within the curtain, and a well without a spring is not a well. The Zohar stresses that every word in the Torah contains supreme secrets. “It is vain for you to rise early” refers to those who are alone, without union as there should be; the “bread of toil” is that of one who has no children; “he gives sleep to his beloved” refers to one whose source is blessed. “There is one, and there is no second” refers to a man without union, without son or brother.