It [man’s soul] is called by five names: nefesh (Genesis 2:7), ruaḥ (Ezekiel 37:14), neshama (Genesis 2:7), yeḥida (Psalms 22:21), ḥaya (Psalms 143:3). Nefesh – this refers to blood, as it is stated: “For blood is the soul [nefesh]” (Deuteronomy 12:23). Ruaḥ – because it ascends and descends, as it is stated: “Who knows the spirit of the sons of man? Does it ascend upward?” (Ecclesiastes 3:21).32Ruaḥ also means wind, which ascends and descends.
Neshama – this refers to man’s intellect, as people say: Intellect is good. Ḥaya – because all of one’s limbs may die, but it [the soul] remains alive [ḥaya] in the body.33A person can lose the use of his limbs, but he cannot live without a soul. Yeḥida – because all of one’s limbs are in pairs, but it [the soul] is solitary [yeḥida] in the body. This is what is written: “If He directs His attention to him, his spirit [ruḥo] and his soul [nishmato] He will gather to him” (Job 34:14).
Rabbi Yehoshua bar Neḥemya and the Rabbis, Rabbi Yehoshua bar Neḥemya said: If God would direct his attention to this person, his spirit would already be in His hand.34If God would so desire, a person would die in his sleep. “And his soul He will gather to him” – [if He would gather the soul into one single place] in his body, the entire man would die. Rather, when a person sleeps, the soul warms the [entire] body so that it does not get too cold and die.
The Rabbis say: If God would direct his attention to this person, and his spirit [ruaḥ] would already be in His hand, “and his soul He will gather to Him” on High,35According to this interpretation, unlike the previous one, “to Him” refers to God. the entire man would die.36If God would take both man’s spirit [ruaḥ] and his soul [neshama] away during sleep, he would die. When a person is sleeping, however, the soul [neshama] [is left within him, and it] warms the body so it will not get too cold and die.
That is what is written: “The spirit [neshama] of man is the lamp of the Lord” (Proverbs 20:27). Rabbi Bisni, Rabbi Aḥa, and Rabbi Yoḥanan say in the name of Rabbi Meir: The neshama fills the entire body, and when a person sleeps, it ascends upward and draws life for him from above. Rabbi Levi said in the name of Rabbi Ḥanina: For each and every breath that a person takes, he must laud the Creator.
What is the source? “Let every soul [neshama] praise God” (Psalms 150:6) – [read instead:] Let every breath [neshima] praise God.