The Gemara discusses Chanukah in the second perek of Maseches Shabbos. The context is the following. The Mishnayos and the Gemara there are discussing the appropriate wicks and oils to use when lighting the Shabbos candles, and from there the Gemara begins to discuss the appropriate wicks and oils to use for lighting the Chanukah candles, and from there the Gemara goes into a long discussion about Chanukah in general. 

In the middle of this discussion of Chanukah, the Gemara quotes as follows,

Amar Rav Kahana, darash Reb Nasan bar Minyomi mishmei d'Rabi Tanchum. A ner Chanukah that is placed above twenty amos is posul.

v'amar Rav Kahana, darash Rav Nasan bar Minyomi mishmei d'Rabi Tanchum- what does it mean when it is written in Parshas Vayeishev, “v'ha'bor reik ein bo ma'yim”? Obviously, if it is empty there is no water. Mayim ein bo aval nechashim v'akravim yesh bo.

There were snakes and scorpions in the pit, and, despite this, Yosef was miraculously saved,

This is a very famous ma'amar Chazal; Rashi[i] on the Chumash quotes these words of Chazal.

The question of course is, why is this statement regarding the bor, the pit, into which Yosef is thrown, quoted here in the middle of the Gemara's discussion of Chanukah? This ma'amar Chazal appears to be totally out of place. The first statement, which discusses the upper limit for the height of the ner Chanukah fits, it is one of the halachos of Chanukah. But the second statement, regarding the pit that Yosef was thrown into, why is it there in the Gemara? We will discuss four approaches to answer this question.

The simplest answer is that the Gemara puts these two statements together because they were both said by the same Amora, Rav Nasan bar Minyomi mishmei d'Rabi Tanchum, and quite often, the Gemara puts together the different statements of an Amora. One reason this is done is as a memory device. One is better able to remember the different statements by grouping the statements of each Amora all together. In this particular case, there is an even stronger reason to say this simple p'shat. These are the only two statements of this Amora mentioned in shas. Therefore, it makes a lot of sense that the “editors of shas,” (that is Rav Nevenzahl's language), would place his two statements together in one place. That is probably the simple p'shat. Rav Nevenzahl goes further[ii] and says that it is very possible that these two statements of Rebbi Tanchum were actually said at the same time, at the same sitting. One statement discusses hilchos Chanukah and the other discusses Parshas Vayeishev, and Parshas Vayeishev always falls out right next to Chanukah.Therefore, it is quite possible that on one Ahabbos of Parshas Vayeishev, Rebbi Tanchum discussed both the parsha and Chanukah as well at the same time. Therefore, the Gemara mentions the two statements together,

There is another explanation[iii] for the connection of the two comments. This second explanation starts with the Ramban[iv]. The Ramban raises the following fundamental question. Based on Chazal that there were snakes and scorpions in the pit, then it is very difficult to understand the brothers' actions. They were trying to kill Yosef, but Hashem miraculously saved him! The Ramban writes that if such a “neis gadol” happened to Yosef it shows that he is a “tzaddik gamur” and “his merits will save him from all evil.” If Hashem saved Yosef in such a miraculous way, then the brothers should have backed out on their plan. Why did they continue their plot to get rid of Yosef and sell him into slavery? How could they try to harm the “mashiach Hashem,” “the anointed one”? The Ramban explains it must be that the brothers did not see the snakes and scorpions. Why not? The Ramban writes that either there were holes in the side of the pit and when the brothers threw Yosef in, the snakes and scorpions ducked into the holes. Or, the pit was very deep and therefore the brothers could not see the bottom. That is the explanation of the Ramban[v].

The Torah Temimah builds on that approach of the Ramban and he explains as follows. He says that we know how deep the pit was. When the Torah describes the brothers throwing Yosef into the pit, the word used is “va'yashlichu,” as opposed to “va’yizriku” which is the more standard word for throwing. This word va’yashlichu is the key. In order to understand the significance of this particular word, we have to review the procedure for the o’las ha’of, the bird offering.

At the beginning of Chumash Vayikra the Torah describes the procedure for the o'las ha'of. The Kohen stands on the so'veiv, the ledge that went around the miz'bey'ach. While he is standing on the so'veiv, he does melika[vi] on the bird. And then, before he offers the body of the bird on the miz'bey'ach, he removes the moor'ah- this is described as the crop or gullet, the upper part of the stomach of the bird.

Chazal explain[vii] that this is done because birds eat from everywhere and much of what they eat is very likely stolen property; they are eating without the owner's permission, and one cannot offer stolen food on the mizbeyach. Once the food is digested inside the bird's stomach and it has changed form, then it is permitted to be offered on the mizbeyach; its changed form is considered a new item[viii]. But while it is still in the gullet before it has been digested, it is considered stolen property and cannot be offered on the miz'bey'ach. Therefore, it must be removed.

The Torah continues “v'hishlich o'sah eitzel ha'miz'bey'ach keidmah el m'kom ha'deshen.” He throws this part of the bird from the soveiv to the makom hadeshen. The makom hadeshen was an area next to the ramp of the mizbeyach. The Mishnayos[ix] teach us that it was located twenty amos (approximately 30 feet) away from the mizbeyach itself. The Kohen would throw the gullet from the soveiv to the makom hadeshen. This was a very long throw. The verb used is “v'hishlich” the root is shin, lamid, chaf. The meforshim[x] point out that this root- shin, lamid, chaf- refers to a very long throw, one that is more than twenty amos.

The Torah Temimah explains that based on this, now we understand why the Torah uses that same root shin, lamed, chaf in connection with the brothers. The Torah here is teaching us that it was a very long throw, it was a very deep pit. This might be the source for the Ramban's answer. They did not just throw Yosef into the pit, they THREW him into the pit. They threw him more than twenty amos; it was a very deep pit. The Torah Temimah connects “va'yashlichu” in Bereishis to the “v'hishlich” in Vayikra. This connection might be the basis for the Ramban's approach to the pesukim in Bereishis.

Based on this, the Torah Temimah writes, now we understand the connection between the two statements in the Gemara. The brothers threw Yosef into the pit; and as the Ramban explains, they did not see the snakes and scorpions. Why not? Because it was too deep. How deep was the pit that they could not see the snakes and scorpions? It was more than twenty amos deep. How do we know that? Based on the use of the root shin, lamid, chuf. And, that is exactly what the Gemara says regarding the ner Chanukah. A ner Chuanukah placed above twenty amos is pasul because one is not able to see it or focus on it, it is too high. It is not in one's normal range of vision. The Torah Temimah explains that this might be the reason why the Gemara put the two statements together because both statements are based on the idea that something beyond twenty amos is difficult to see. This is the second explanation of the connection of the two statements. And again, this was made famous by the Torah Temimah.

[i] Breishis 37,24

[ii] See Yerushalayim b'Moadeha, Shabbos Kodesh, Vol. 1 p. 148.

[iii] This approach was made famous by the Torah Temimah (Breishis 37, note 20).

[iv] Breishis 38,22.

[v] This approach of the Ramban also explains another question regarding Reuven. Reuven was trying to save Yosef. But, if there were snakes and scorpions in the pit, then it is difficult to understand how Reuven thought this would save Yosef. Ramban's approach that the brothers, including Reuven, did not know about the snakes and scorpions, explains Reuven's actions as well. Reuven was hoping that Yosef would be in the pit, and he would not be killed, and later he would come back and save him.

[vi] See Rashi (Vayikra 1,15) for a precise description of  melika.

[vii] Rashi (Vayikra 1,16)

[viii] Abarbanel, cited in the Sha’arei Ahron (Vayikra 1,16).

[ix] See Middos Ch. 5 Mishnayos 1-2 and Tamid end of Ch. 1

[x] See the ‘Mefaresh’ to Maseches Tamid 28b.