In the section of Parshas HaChodesh, G‑d says to Moshe and Aharon: “This month (Nissan) shall be the head of the months to you; it shall be the first month of the year.”1 This directive encompasses the commandment of maintaining a lunar calendar.2

In earlier times, the beginning of each new month was confirmed by the sighting of the new moon by two credible witnesses, together with astronomical calculations by members of the Jewish court (Sanhedrin).3

Since Torah rules that the testimony of honest witnesses is to be believed,4 why are we told that the sighting of the new moon must be corroborated by calculations? Evidently the exact moment of the new moon is of such import that independent verification is required. What is so special about this command that it requires independent validation?

Concerning the directive in the verse, “This month shall be the head of the months,” our Sages comment: “By right, the Torah should have begun with [this command],”5 for, as Rashi notes, “This is the first commandment the Jews received.”6

Why, indeed, is this the first commandment? Would it not have been more reasonable for the Torah’s first command to be the first of the Ten Commandments, “I am the L‑rd your G‑d...,”7 which commands us to accept G‑d’s Divine sovereignty?8 After all, this acceptance is the bedrock of our religion and the basis for the performance of all commandments.

This may be explained as follows: While the injunction “I am the L‑rd your G‑d” is fundamental to the performance of commandments, “This month shall be...” represents the ultimate purpose and goal of all commandments. For this reason it is the first command.9

Why is this so? Because the purpose of Torah and its commandments is so that Jews should bring something new into this world through them.

This is alluded to in the specific words of the command: “This month.” The Hebrew word for “month” ischodesh, which is etymologically related to the word chiddush (“novel” or “new”).10 This novelty was entrusted “to you,” the Jewish people,11 for it is through the performance of Torah and mitzvos by the Jewish people that they transform this world into “a dwelling place for G‑d.”

Making a “dwelling place for G‑d in the nethermost level,”12 i.e., transforming this physical world into a G‑dly abode, consists of two aspects: a) the “nethermost level” must be made fit to serve as G‑d’s dwelling place; b) G‑d’s essence must be revealed here, just as a person’s entire essence is found in his house.13

Both of these accomplishments require a chiddush, or something new to be created.14 In order for the “nethermost level” to become a dwelling place for G‑d, total nullification of self is necessary — a novel experience for an entity whose whole being lies in its awareness of self.

There is an element of chiddush on G‑d’s part as well, for while the whole of Creation emanates from but a luminous fragment of G‑d’s Essence, G‑d’s dwelling in this world means that His very Essence is present.

Just as “This month shall be for you” emphasizes the raison d’être of Torah and mitzvos in relation to the world as a whole, so, too, does it reveal the effect of Torah and its commandments upon the Jewish people.

The Jewish people are likened by our Sages to the moon.15 Their development and growth — accomplished by their performance of Torah and mitzvos — demonstrates their state of spiritual chiddush and ascent.

This is brought about within Jews in one of two ways: a) elevating their inner soul levels through intellectual spiritual service; b) elevating their essential soul levels through their nullification to the Divine Will insofar as it transcends intellect.

Both these manners of Divine service are expressed in the way in which the new month is determined:

The internal and intellectual level of service is alluded to by declaring the new month according to astronomical calculation — a completely rational decision.

The sighting of the new moon by witnesses alludes to the level of service that transcends rationality. For a person believes what he witnesses with his own eyes, even when it defies all the rules of logic.

Based on Likkutei Sichos, Vol. XXI, pp. 64-67.