The Sfas Emes (5632, 'א נר) writes, "This has remained for all generations. There is help during these days to do Hashem's will more than the standard order and hashgachah of the rest of the year. It is a path of miracles and wonders."
On these days, we open an opening of a מחט, and Hakadosh Baruch Hu opens up for him so much more.
Someone came to the Magid of Mezritz zt'l seeking advice. He said that he couldn’t overcome and push away the many thoughts that came to his mind while he was davening and learning. The Magid advised him to go to his student, the Or HaMeir, for counsel in this matter.
This man immediately went to the Or HaMeir's house. He arrived at nighttime and knocked on the door, but no one answered. It was a very cold night. He knocked again and again, but the door remained shut. Sometime later, he met the Or HaMeir and he asked him why he didn't answer the door. "The Magid sent me to speak to you!" The Or HaMeir replied, "I am the baal habayis of my house. I decide who comes in and who doesn’t. You too must know that you are a baal habayis. You are the baal habayis over your mind. You can accept into your mind the thoughts that you want to think and block out whatever you don't want to think about."
With this story, we can explain the Chazal, which says, "So the ner Chanukah will be on the left, the mezuzah on the right, and the baal habayis, dressed in tzitzis, between them." He is called specifically baal habayis to indicate that with this mitzvah, it is mesugal that he will become a baal habayis, a person in control of his thoughts.
We can also explain that Chazal are hinting that if he is a baal habayis, that he controls his thoughts, his performance of the mitzvah of Chanukah is on a much higher and perfect level.
The Bnei Yissaschar (Hallel 1) teaches that Chanukah lecht saves from Gehinom. Kabalah sefarim say that Gehinom is in the north, and north is to the left. (When facing mizrach, north is to the left.) In the zechus of the Chanukah lecht which are placed on the left side of the doorway, we are spared from the fire of Gehinom.
If Chanukah lecht are within the first three tefachim of the ground, it is pasul (see Shulchan Aruch 671:6). Tzaddikim taught that this hints that although Chanukah is about Hashem's light going down to people who are below ten tefachim, a person must do at least something to elevate himself. He can't be all the way down on the ground. He must take the first step towards improvement, and then Hashem will elevate him.
The dreidel has the four letters ש"נגה – the roshei teivos of שם היה גדול נס, "A great miracle occurred there." In this way, the dreidel publicizes the miracle. But the dreidel is small. Wouldn't it be better to hang up large posters with the words שם היה גדול נס on them? Wouldn't that be a greater pirsumei nisa, publicization of the miracle? The answer is that a poster stands in one place, whereas a dreidel moves around. Man's obligation is to be active, move, perform, and not remain stuck at one level.
This is hinted in the Gemara (Shabbos 22:) כלום ולא עשה לא ועומד חנוכה נר תופש היה, "He was holding a Chanukah menorah and standing, he didn't do anything at all." Rebbe Yisrael of Tchortkov zt'l said that the problem is that he is standing in one spot. A Yid should be growing and rising from level to level.
Beis Shamai hold והולך פוחת, that the first night of Chanukah, eight lights are lit, and each night, we light one less. Beis Hillel say והולך מוסיף, that the first night we light one, and each day, we add another lamp (see Shabbos 21:). The Chidushei HaRim zt'l points out that they both agree that one shouldn't be stagnant. One must constantly change. You cannot light the same number of lecht each night. This teaches us that a person must always grow and elevate himself, especially on Chanukah.
The Sifsei Tzaddik (Chanukah 3) quotes his grandfather, the Chidushei HaRim zt'l who told the following story:
Once, during Chanukah, chasidim came to the Chozeh of Lublin to ask for help with a certain moser (informer) who lived in their city and caused them a lot of tzaros. They wrote the moser's name on a kvittel and gave it to the Chozeh. When the Chozeh saw the kvittel he said, "But this person shines in all worlds!" The chasidim were shocked. How could that be? But they didn't dare to ask for an explanation. A bit later, they mentioned his name again to the Chozeh, and this time the Chozeh gave them a brachah that they should be saved from the moser's evil deeds.
When the opportunity arose, they asked the Chozeh for an explanation. Why did he first say that the man's neshamah shined in all worlds, and afterward, he saw that he was indeed a great rasha? The Chozeh explained that the first time they gave him the kvittel, this man was lighting Chanukah lecht. This brought a great light to his neshamah.
Generally, people learn from this story the power and potential of Chanukah lecht, that it can bring light and kedushah even to the neshamos of resha'im. But there is another lesson here: Shortly after the moser lit the Chanukah lecht, the Chozeh was able to see that he was a rasha. This is because it is true that Chanukah lecht have the potential to sanctify us, but it is up to the person to continue on that path. He must desire to grow and improve his ways. If he doesn't, after lighting the Chanukah lecht, it will not be long before he returns to where he was before, chalilah.
לעול כשור "like an ox that carries a yoke" is an expression used to mean that one should accept the yoke of Torah and mitzvos לעול כשור, like an ox that carries its yoke. Rebbe Bunim of Peshischa zt'l (Sfas Emes Avos, p.23) explains that when an ox plows a field, it never looks back at the freshly plowed field to see what it accomplished. Its focus is always to plow forward. This is how a person should serve Hashem. He shouldn't look back on his accomplishments. His focus should be always on the future, not on the past. When one follows this counsel, he will never come to yeush. He will never lose hope and despair. But when one looks back, he may be disappointed, due to his lack of accomplishment.
The Yevanim decreed that every Yid must write on their oxen's horns that they don't have a portion with the G-d of Yisrael. We can explain the significance of ox's horns in that they didn't want the Yidden to serve Hashem with the kind of service that oxen do. The Yevanim wanted them to look back, to delve into their failures and shortcomings because that would bring them to yeush.
Also, the Sfas Emes (Chanukah 5635) writes, "These days, there is help from above to acquire in large measurements yiras Shamayim and to overcome and conquer the yetzer hara." The Sfas Emes explains that this is hinted in the Chazal that says (Shabbos 21:), "The mitzvah of Ner Chanukah, is to place it by the doorway, on the outside," and the outside represents yiras Shamayim. This is because the Gemara (Shabbos 31:) says, "Any person who has Torah without yiras Shamayim is like a caretaker who was given the keys to the inner door but didn't receive the keys to the outer door. How will he go inside?" This Gemara refers to yiras Shamayim as "the outer door". We light Chanukah lecht outdoors, which tells us that with Chanukah lecht, we can attain yiras Shamayim.
It states (Mishlei 20:27) ֵיַדְרח ָּלכ ֵׂשחֹפ ָםָדא ַתׁמְנִש 'ה נֵר ןָטב, "Man's soul is Hashem's ner/lamp, which searches all the innermost parts." The Beis Avraham zt'l says (Chanukah) that חופש can be translated as freedom (see Shemos 21:26 ישלחנו לחפש, "he shall set him free"). The Chanukah lecht frees the neshamah of a Yid from all tumos that are hidden within him.
Therefore, let every person strengthen himself and invest in reviving and renewing his avodas Hashem. When one tries, Hashem will help him.