Our Gemara describes an interlude with Rabbi Yochanan, where he misjudges a student, Rav Kahana, several times:

 

Originally Rav Kahana was seated in the front row of the Shiur, as his reputation preceded him. However he was under instructions by his master, Rav, to not ask any questions in Rabbi Yochanan’s Shiur for seven years. Therefore, he appeared in the Shiur as a lackluster scholar whose hype was not commensurate with his performance. (What Rav’s intentions for his pupil is unknown, but it seemed to be some kind of penitential exercise or to teach humility.) 

 

The story continues:

 

The next day, they seated Rav Kahana in the first row, in front of Rabbi Yoḥanan. Rabbi Yoḥanan stated a halakha and Rav Kahana did not raise a difficulty, in accordance with Rav’s instruction. Rabbi Yoḥanan stated another halakha and again, Rav Kahana did not raise a difficulty. As a result, they placed Rav Kahana further back by one row. This occurred until he had been moved back seven rows, until he was seated in the last row. Rabbi Yoḥanan said to Rabbi Shimon ben Lakish: The lion you mentioned has become a fox, i.e., he is not knowledgeable.

 

Unable to bear this isolation, Rav Kahana said to himself: 

 

May it be God’s will that these seven rows I have been moved should replace the seven years that Rav told me to wait before raising difficulties to the statements of Rabbi Yoḥanan. He stood up on his feet and said to Rabbi Yoḥanan: Let the Master go back to the beginning of the discourse and repeat what he said. Rabbi Yoḥanan stated a halakha and Rav Kahana raised a difficulty. Therefore, they placed him in the first row, and again, Rav Yoḥanan stated a halakha, and he raised a difficulty.

 

Rabbi Yoḥanan was sitting upon seven cushions [bistarkei] so that he could be seen by all the students, and since he could not answer Rav Kahana’s questions, he removed one cushion from under himself to demonstrate that he was lowering himself out of respect for Rav Kahana. He then stated another halakha and Rav Kahana raised another difficulty. This happened repeatedly until Rabbi Yoḥanan removed all the cushions from underneath himself until he was sitting on the ground. 

 

Rabbi Yochanan, seemingly in remorse for misjudging Rav Kahana, lowers his seat to Rav Kahana’s level. Unfortunately, Middos are difficult to change, and somehow Rabbi Yochanan misjudges Rav Kahana again, with even more disastrous consequences.  

 

(I wouldn’t be so bold as to criticize Rabbi Yochanan, except for the fact that the narrative of the Gemara is so plainly indicating Rabbi Yochanan’s errors and his own efforts to correct them.  The Gemara obviously recorded this for posterity so that we may learn from it):

 

Rabbi Yoḥanan was an old man and his eyebrows drooped over his eyes. He said to his students: Uncover my eyes for me and I will see Rav Kahana, so they uncovered his eyes for him with a silver eye brush.

 

Once his eyes were uncovered, Rabbi Yoḥanan saw that Rav Kahana’s lips were split and thought that Rav Kahana was smirking at him. As a result, Rabbi Yoḥanan was offended, and Rav Kahana died as punishment for the fact that he offended Rabbi Yoḥanan. The next day, Rabbi Yoḥanan said to the Rabbis, his students: Did you see how that Babylonian, Rav Kahana, behaved in such a disrespectful manner? They said to him: His usual manner of appearance is such, and he was not mocking you. Hearing this, Rabbi Yoḥanan went up to Rav Kahana’s burial cave and saw that it was encircled by a serpent [akhna], which had placed its tail in its mouth, completely encircling the cave and blocking the entrance. Rabbi Yoḥanan said to it: Serpent, serpent, open your mouth and allow the teacher to enter and be near the disciple, but the serpent did not open its mouth to allow him entry. He then said: Allow a colleague to enter and be near his colleague, but still the serpent did not open its mouth. Rabbi Yoḥanan said: Allow the disciple to enter and be near the teacher, referring to Rav Kahana as his own teacher. The snake then opened its mouth for him to allow him entry. Rabbi Yoḥanan requested divine mercy from God and raised Rav Kahana from the dead.

 

Rabbi Yochanan must seek out his student Rav Kahana by his grave, and is only allowed admittance by a menacing snake until he humbles himself and states that he is a student of Rav Kahana, instead of a master.

 

The menacing serpent that Rabbi Yochanan saw was a snake with its tail in its mouth, known in the Gemara as an “Achnai”. This is an ancient symbol, called the Ouroboros, which seems to connote the eternal cycle of life: Likely this is symbolized by the tail in its mouth, and possibly also because a snake sheds its skin and goes through a rebirth of sorts. The first known archaeological representation of the Ouroboros, is on one of the shrines enclosing the sarcophagus of Tutankhamun (see https://en.wikipedia.org/wiki/Ouroboros ) 

 

The ancient tradition of this Ouroboros might also be related to the Leviathan, which has connotations of a powerful force present at the time of creation which God subdued (see Yeshaiyahu chapter 27, Iyov chapter 40, Bava Basra 74b, and Rashi Bereishis 1:21 quoting a midrash.) The Zohar (Tikkunei Zohar 52:2) describes it as similar to a circular intestine in the body. Similarly, the word Akalason found in those same verses in Yeshaiyahu (27) could be translated as a twisted serpent.  Thus the Leviathan, the Akalason and the Ouroboros seem to be one in the same. The Babylonian epic of Baal also describes a primordial battle of Baal with a giant serpentine creature. Even if it became distorted with idolatrous imagery, the Ouroboros may have been part of a shared mystical tradition from many ancient sources, originally a Jewish tradition. See Rambam (Laws of Idolatry 1:1), where he characterizes the original idolaters as having descended from Adam’s progeny who worshiped God, but then distorted their teachings.  We also might wonder if King Tutankhamun, utilized the Ouroboros-Leviathan symbol as part of a tradition learned from Joseph. The Midrash (Sotah 36b) tells us that Yosef taught Pharaoh Hebrew; perhaps he taught him a whole lot more. 

We also find the word Achnai coming up in regard to the famous dispute in Bava Metzia (59b) where the rabbis “argue” with God about a halacha. In that foundational aggadah, God has to concede to HIS talmidim, the rabbis, because “Torah is not in heaven.” And God says, as a proud father, “Nitzchuni Banai - my children have been victorious over me.” The message of eternity and humility become intertwined. Life is a great cycle of birth, death and renewal, as God Himself has to make room for the physical forces to manifest, out of their own free will to choose to strive and become elevated, and reunited with Him (see Derech Hashem, chapter one). The student and teacher all become one.