The Upanishads are Sanskrit texts of commentary on the four primary Vedic religious classics of Hinduism (the Rig, Sama, Yajur, Atharva).

This passage is a commentary on dream analysis contained in one of them:

“Dreams, therefore, are due to repressed desires. This is one of the causes behind dreams. This is the only factor that the psychoanalysts of the West emphasise. But Indian psychologists and psychoanalysts, like the Raja Yogins and the philosophers of the Vedanta, have touched another aspect of dream. The dreams may be, to some extent, of course, the results of complexes created by frustrated desires. But, this is not wholly true. Dreams may be due to other reasons also; one such reason being the working of past Karma. The effects of past Karmas, meritorious or unmeritorious, may project themselves into dream when chances are not given to them for expression in waking life. Also, a thought of some other person may affect you. A friend of yours may be deeply thinking of you; and you may have a dream of him, or you may have a dream with experiences corresponding to his thoughts. Your mother may be far away, crying for you, and her thought can affect you; you may have a dream. All this is equal to saying that a telepathic effect can produce dreams. In the case of spiritual seekers, Guru’s grace can cause a dream; and catastrophic experiences that one may have to pass through in the waking world may pass lightly as a dream experience by his grace. Due to the power of the Guru, one may have a dream suffering, instead of a waking one…….. The reason is that you oppose their function in waking life, due to the assertions of the ego. You counteract Isvara’s working and Guru’s blessing by the action of your own egoism. But, in dreaming, the ego subsides, to some extent. You become more normal, one may say, and you approximate yourself more to reality, rather than to artificiality, in dream. Thus, it is easier for these powers to operate in dream than in waking. .”

— The Mandukya Upanishad on dreams, elucidated by Swami Krishnananda