גמ׳ אמר רב חנן בר רבא קלנדא ח' ימים אחר תקופה סטרנורא ח' ימים לפני תקופה וסימנך (תהלים קלט, ה) אחור וקדם צרתני וגו' ת"ר לפי שראה אדם הראשון יום שמתמעט והולך אמר אוי לי שמא בשביל שסרחתי עולם חשוך בעדי וחוזר לתוהו ובוהו וזו היא מיתה שנקנסה עלי מן השמים עמד וישב ח' ימים בתענית [ובתפלה] כיון שראה תקופת טבת וראה יום שמאריך והולך אמר מנהגו של עולם הוא הלך ועשה שמונה ימים טובים לשנה האחרת עשאן לאלו ולאלו ימים טובים הוא קבעם לשם שמים והם קבעום לשם עבודת כוכבים
GEMARA: Rav Ḥanan bar Rava says: When are these festivals celebrated? Kalenda is celebrated during the eight days after the winter solstice, and Saturnalia is celebrated during the eight days before the winter solstice....
With regard to the dates of these festivals, the Sages taught: When Adam the first man saw that the day was progressively diminishing, he said: "Woe is me; perhaps because I sinned the world is becoming dark around me and will ultimately return to the primordial state of chaos and disorder. And this is the death that was sentenced upon me from Heaven, as it is written: “And to dust shall you return” (Genesis 3:19).
He arose and spent eight days in fasting and in prayer. Once he saw that the season of Tevet, i.e., the winter solstice, had arrived, and saw that the day was progressively lengthening he said: "Clearly, the days become shorter and then longer, and this is the order of the world." He went and observed a festival for eight days. Upon the next year, he observed both these eight days on which he had fasted on the previous year, and these eight days of his celebration, as days of festivities. He, Adam, established these festivals for the sake of Heaven, and the gentiles established them for the sake of star worship.
ולחשך קרא לילה. פי׳ חז״ל ריש מס׳ פסחים קרא הקב״ה לחשכה ופקדה אלילה. למדונו רבותינו שלא נימא דחשך הוא העדר האור לבד. כמו בעצם היום כשסותמים החלונות נעשה חשך. וא״כ אינו בריאה. אבל באמת חשך הוא בריאה בפ״ע ג״כ כדכתיב ובורא חשך וטעות גדול לומר שחשך אינו אלא העדר האור. אלא ה׳ עושה שניהם כמו כחות הקדושה והטומאה. (ועי׳ מש״כ להלן כ״ז ט׳) ואל תקשה מאי מועיל בריאה זו. הרי בלא בריאה יהי׳ חשך בהעדר אור. אבל כבר הורונו חז״ל (בפ׳ חלק ובב״ר פ׳ נח ובירושלמי פסחים פ׳ א׳) דאור האש אינו מנהיר ביום במקום חשך כמו בלילה שבו החשך מושל. ומזה הבינו אנשי מעלה בישיבתם בחשך מתי יום ומתי לילה. וכמו באור וחשך של יום ולילה. כך בכ״ד שנמשל לאור וחשך כך הוא. דיש כמה טובות שאין האדם מרגיש כ״כ בעת שהוא מוצלח עד שנעשה עני ומכיר הטובה. וכך הטביע ית׳ בעולמו.
And to the darkness, He called night: The Sages, of blessed memory, explained in the beginning of Tractate Pesachim, that the Holy One, blessed be He, called to darkness and appointed it over the night. [By this,] our Rabbis taught us that we should not say that darkness is only the absence of light, like when - in the middle of the day - we close the windows, it becomes dark. For, if so, it would not be a creation. But in truth, darkness is a creation, on its own as well, as it is written (Isaiah 45:7), "and created the darkness." And it is great distortion to say that darkness is only the absence of light. But rather, God makes both of them, just as He concerns Himself over holiness and impurity. (And see what I have written later, Genesis 27:9.) And to the question, "what does this creation help, behold, even without [its] creation, there would be darkness in the absence of light?," the Sages, of blessed memory, have taught us (in the chapter "Chelek" and in Bereshit Rabbah, Parshat Noach and in the Talmud Yerushalmi in the first chapter) that the light of a fire does not shine during the day in a dark place, [with the same brightness] as it does at night when darkness reigns. And from this, lofty people were able to know while they were sitting in the dark, when it was day and when it was night - in which darkness rules. And as it is with the light and darkness of day and night, so too is it thus with all things that are compared to light and darkness; since there are many bounties that man does not feel so much when he is successful, until he becomes poor and he sees the bounty [that he once had]. And [He], may He be blessed, implanted this into His world.
The soul/lifebreath of the human is the lamp of the LORD [or: The light of God is the soul of the human] revealing all the innermost chambers.
Katherine May, "Wintering: The Power of Rest and Retreat in Difficult Times," pp. 12-13
We're not raised to recognise wintering or to acknowledge its inevitability. Instead, we tend to see it as a humiliation, something that should be hidden from view lest we shock the world too greatly. We put on a brave public face and grieve privately; we pretend not to see other people's pain. We treat each wintering as an embarrassing anomaly that should be hidden or ignored. This means we've made a secret of an entirely ordinary process and have thereby given those who endure it a pariah status, forcing them to drop out of everyday life in order to conceal their failure. Yet we do this at a great cost. Wintering brings about some of the most profound and insightful moments of our human experience, and wisdom resides in those who have wintered.
In our relentlessly busy contemporary world, we are forever trying to defer the onset of winter. We don't ever dare to feel its full bite, and we don't dare to show the way that it ravages us. An occasional sharp wintering would do us good. We must stop believing that these times in our lives are somehow silly, a failure of nerve, a lack of willpower. We must stop trying to ignore them or dispose of them. They are real, and they are asking something of us. We must learn to invite the winter in. We may never choose to winter, but we can choose how.