“Rabbi Yoḥanan said in the name of Rabbi Shim’on son of Yoḥai: Every mitsvah which the blessed Holy One gave to Israel, He gave to them publicly, except the Sabbath which He bestowed upon them in secret, for it is said: ‘Between Me and the Israelites it is a sign for all time’ [the word לְעֹלָם (le-olam), for all time, is written defectively as if derived from, לְעֱלָם (le-elam), to conceal] (Exodus 31:17). If so, idolaters should not be punished on its account [cf. BT Avodah Zarah 2b]!—the Sabbath He indeed made known to them but its reward He did not make known to them. Or you can say: Its reward too He made known to them, נְשָׁמָה יְתֵירָה (neshamah yeteirah), luxuriant life-breath, He did not make known to them. For Rabbi Shim’on son of Laqish said: On the eve of the Sabbath the blessed Holy One gives to man abundance of soul and at the close of the Sabbath He withdraws it from him, for it says: He ceased וַיִּנָּפַשׁ (va-yinnafash), and caught His breath (Exodus 31:17)—once [the Sabbath] has ceased, וַוי אֲבֵדָה נֶפֶשׁ (wawi avedah nefesh), woe for that loss of life-breath! [וַיִּנָּפַשׁ (va-yinnafash), and caught His breath, is numerically equivalent to מָוֶת (mavet), death (Rabbi Levi Isaac Krakovsky)]” (BT Beitsah 16a, cf. BT Ta’anit 27a).
“His disciples asked: What is חֹלֶם (ḥolem)? He said: נְשָׁמָה (Neshama), soul—if תִּשְׁמַע (tishema), you heed, her, your body will be תַּחְלִים (taḥlim), revived, in the time to come. And should you rebel against her? [Your requital] shall come back—חוֹלִים (ḥolim), diseases—on your head (Obadiah 1:15), and חֶלְיָה (ḥelyah), jewelry [or: illness], on her head” (Bahir §40).
“When the human was created, what is written? You clothed me in skin and flesh (Job 10:11). What then is the human if not skin and flesh, and bones and sinews? But surely the human being is nothing but soul! And these that we have mentioned—skin, flesh, bones, and sinews are all merely a garment; they are a person’s clothing not the human. And when a person departs, he is stripped of those garments that he is wearing” (Zohar 2:76a).