Rabbi Dovber begins with two questions on the verse, For You, G‑d, are my Lamp; and G‑d will illuminate my darkness. The first question is: Why is G‑d's Name invoked twice, seemingly bisecting the verse into two separate statements?

To answer, Rabbi DovBer quotes the verse, The soul of man is a Lamp of G‑d. He explains that the four letters of the Divine Name are manifested in the Jew.  Each letter relates to a different aspect of the inner person. This is what is meant by, For You, G‑d, are my Lamp. When a person sins, the letters can become defective but can be repaired through teshuvah. This is the meaning of the second half of the verse, and G‑d will illuminate my darkness, i.e., when the person performs teshuvah.

Rabbi Dovber then begins to describe the lamp, which consists of five parts: 1) the wick; 2) the flame, which consists of two parts: the dark radiance that burns close to the wick, consuming it, and 3) the flame's bright radiance; 4) the oil; 5) the vessel (that contains the oil and wick).

1.
THE CHANUKAH LAMP AND THE SOUL

Questions

"For You, G‑d, are my lamp; and G‑d will illuminate my darkness."1 We can ask: Why is G‑d's Name invoked twice? The verse ought to read: "For You, G‑d are my lamp, Who will illuminate my darkness." Further, what is the force of the conjunctive 'and' in the phrase "and G‑d will illuminate"? Why not simply say, "G‑d will illuminate"?

The Divine Name In The Soul

Says King Solomon: "The lamp of G‑d is the soul of a person."2 The soul is literally termed "the lamp of G‑d" because within it3 shine the four letters of Havaya.4 Yud is expressed by chochmah5 in the brain; hey by binah6; vav is expressed by the emotions in the heart; and the second hey is expressed by the person's actions.7 This is the tzelem elokim,8 the divine form within the person, symbolically constituting four letters. If one causes a flaw in his soul in the letter yud, such as by profaning the Shabbat or by not studying Torah,9 the divine radiance of the yud is withdrawn. Or, if one causes a flaw in the letter hey [the divine radiance of that letter is withdrawn], and so on, as we say in the confession of the Shema prayer before retiring at night.10

Thus, "and G‑d will illuminate my darkness" — even after the radiance of tzelem elokim in the four letters of Havaya has been flawed. For this reason the verse repeats itself, first stating, "You G‑d are my lamp," and then [after the initial radiance is withdrawn, through transgression], as a result of teshuvah, "G‑d will illuminate my darkness."11

The Soul as a Shining Light

We have to understand how the four letters of Havaya are vested in the soul. First,12 let us consider the nature of the souls of the Jewish people, which relate to the seven lights of the Menorah in the Temple. What indeed is the true nature of these lamps? As the Sages comment: "Does He need light?"13 Rather, the Menorah is actually a testimony to the Jewish people that the Shechinah14 dwells among them15.

Four Aspects Of The Lamp

At this point we should understand that in a lamp there are, in general, four aspects. The first is the wick, which illuminates because of the flame that burns from it. Then there is the flame itself that burns from the wick, which includes two levels, expressed in two colors of the light.16 One is the dark color which is close to the wick, and is called "dark radiance," which burns and gradually consumes the wick; the other, higher up, is the white flame, which is called "the light which illuminates" and also the "bright radiance." The fourth aspect of the lamp is the oil which flows into the wick and is absorbed in it. Without the oil, the flame would not burn from the wick at all, but would leap away17 and be extinguished.

Through bonding and connecting these four aspects — i.e.: the oil, the wick, and two colors of flame — there is manifest "light." For if the flame did not cleave to the wick there would be no light at all — it would vanish altogether. Only when the flame cleaves to the wick, consuming it gradually, can this flame be termed "illuminating light" which is the essential quality of light. This quality is achieved particularly by the lower aspect of the flame, the "dark radiance" which holds to the wick and burns from it, gradually consuming it.

Oil

However, it is the oil which achieves the bonding of the two-tiered flame with the wick. Without oil the flame would either vanish, or swiftly consume the wick, extinguishing the light. But when the oil flows through the wick, the flame is drawn towards it and burns properly. The wick does not quickly burn away, and the flame lasts a long time.

This is a contrary process: the oil both draws the flame to cleave well to the wick,18 and on the other hand prevents the wick from being swiftly burned up.19 A further effect of the oil is that by drawing the flame it makes it particularly bright and pure. This is the white flame which shines as a consequence of the purity of the oil. The oil thus has two different effects: one is causing the [dark] flame to cleave to the wick [i.e. preventing it from consuming the wick and thus] extending the time that the flame will burn; and the other is generating the bright pure radiance, which illuminates.

(A burning piece of wood is just a burning fire, which is not considered to be giving as much illumination as the light of a lamp of oil and wick. This is the difference between light and fire.)

So it is understood that the oil joins the two-colored radiance with the wick: a) it connects the black fire of the flame to the wick, which burns and consumes the wick as long as it is joined to it, and is also the main contact of the flame with the wick; b) it connects the higher bright radiance to the wick, and is also the source of its brightness.

This double effect comes from the consumption of the oil in the flame. The oil is drawn through the wick, attracted by the flame, which produces the two colors of light described above. In fact, these two kinds of flame are both initially included in the oil. The effect of burning the oil is that the two kinds of flame emerge from concealment and are now revealed.

Chanukah

On account of this quality of the oil, the Sages decreed concerning the mitzvah of the Chanukah lamp that there are some oils which one may not use, because they do not flow properly in a wick.20 In the Chanukah lamp it is important that there should be the two colors of flame around the wick, and that the light should last a certain time. This is impossible without good, clear oil which flows in the wick, as will be explained.21

A Fifth Aspect

(There is also a fifth aspect of the [Chanukah] lamp — and this is the vessel of the lamp itself, containing within it all the other four aspects: the oil, the wick, and the two kinds of flame. Without the vessel of the lamp there would be no light at all.22)

SUMMARY

For You, G‑d, are my lamp; and G‑d will illuminate my darkness.

Question: Why is the verse bisected? Why invoke G‑d's name twice? And what is the implication of the conjunctive 'and'?

Answer: Man is created in the Divine form. The soul contains the four letters of the Divine Name Havaya. Yud — wisdom; hey — comprehension; vav — emotions; hey — action.

If a soul becomes flawed and darkened by sin, it can be repaired through teshuvah. This is implied by "and G‑d will illuminate my darkness."

The soul of man is a lamp of G‑d. The Rebbe analyzes the lamp structure to help us understand the soul.

An oil lamp has five parts:

1) the vessel (holding oil and wick);

2) the wick;

3) the dark radiance, burning close to the wick and consuming it;

4) the illuminating radiance;

5) the oil.

The oil has two functions:

1) The oil plays a conflicting role, as it both fuels the destruction of the wick and yet ultimately sustains it. The oil causes the flame to act against its nature, i.e., to remain attached to the wick; and it sustains the wick, enabling it to be consumed only gradually.

2) The quality of the flame depends on the quality of the oil. Thus, the oil itself must possess multiple colors or qualities that eventually appear in the burning flame.