This chodesh (new moon, month) shall be for you the head of months; it shall be for you the first of the months of the year (12:2)

G‑d showed Moses the new moon at its moment of rebirth, and said to him: “When the moon is reborn, mark the beginning of a new month.”


There was a large courtyard in Jerusalem called Beth Yaazek, where all the witnesses (who had seen the appearance of the new moon) used to assemble, and the beit din (rabbinical court) used to examine them. They used to entertain them lavishly there, so that they should have an inducement to come . . .

The pair of witnesses who arrived first were crossexamined first. The senior of them was brought in and they said to him: “Tell us how you saw the moon—in front of the sun or behind the sun? To the north of it or the south? How big was it, and in which direction was it inclined? How broad was it?” . . . Rabban Gamaliel used to have diagrams of the phases of the moon on a tablet on the wall of his upper chamber, and he used to show them to the unlearned and ask, “Did it look like this or this?” . . .

After that they would bring in the second witness and question him. If their accounts tallied, their evidence was accepted. The other pairs were questioned briefly—not because they were required at all, but so that they should not be disappointed and discouraged from coming (the next time).

The head of the beit din would then proclaim: “Sanctified!” and all the people would repeat after him, “Sanctified! Sanctified!”

(Talmud, Rosh Hashanah ch. 2)

What blessing was to be recited by one who beholds the new moon, in the period when Israel used to sanctify the new month? Some of the sages hold: “Blessed be He who renews the months.” Others say: “Blessed be He who consecrates the months.” And others say: “Blessed be He who hallows Israel,” since unless Israel sanctify it, it is not sanctified at all.

(Midrash Rabbah)

The people of Israel set their calendar by the moon, because they are the moon of the world.



The moon begins to shine on the first of the month, and increases in luminance till the fifteenth day, when her orb becomes full; from the fifteenth till the thirtieth day her light wanes, till on the thirtieth it is not seen at all. With Israel too, there were fifteen generations from Abraham to Solomon. Abraham began to shine . . . Jacob added to this light . . . and after them came Judah, Peretz, Chetzron, Ram, Aminadav, Nachshon, Salmon, Boaz, Obed, Jesse and David. When Solomon appeared, the moon’s orb was full. . . . Henceforth the kings began to diminish in power. . . . With Zedekiah [in whose time the Holy Temple was destroyed], the light of the moon dimmed entirely.

(Midrash Rabbah)

It is written (Genesis 1:16), “G‑d made the two great luminaries”; but then it says, “The great luminary . . . and the small luminary”?

[Indeed, at first they were both great; but then] the moon said to G‑d: Master of the Universe! Can two kings wear the same crown?

Said G‑d to her: Go diminish yourself.

Said she to Him: Master of the Universe! Because I have said a proper thing, I must diminish myself?

Said He to her: You may rule both during the day and at night.

Said she to Him: What advantage is there in that? What does a lamp accomplish at high noon?

Said He to her: The people of Israel shall calculate their dates and years by you.

Said she to Him: But the sun, too, shall have a part in that, for they shall calculate the seasons by him.

Said G‑d: The righteous shall be called by your name—“Jacob the Small,” “Samuel the Small,” “David the Small.”

Still G‑d saw that the moon was not appeased. So G‑d said: “Offer an atonement for My sake, for My having diminished the moon.” This is the significance of what Reish Lakish said: Why does the he-goat offered on Rosh Chodesh (the first of the month) differ from the others in that it is specified as for G‑d? G‑d is saying: This he-goat shall atone for My diminishing of the moon.

(Talmud, Chullin 60b)


The months of the year are lunar months, as it is written: “This chodesh shall be for you the head of months.” So said our sages: G‑d showed Moses the figure of the [new] moon in a prophetic vision, and said to him: “Thus you should see and sanctify.”

However, the years which we figure are solar years, as it is written: “Keep the month of spring” [i.e., ensure that the month of Passover is always in the spring season].

The solar year is eleven days longer than a year of [twelve] lunar months. Therefore, when this surplus accumulates to the amount of 30 days—either a little more or a little less—they add an extra month, so that the year has 13 months; this is what is called a shanah meuberet (“pregnant year”). [This is done] because one cannot make the year to consist of so many months plus so many days, since the verse says, “[It shall be for you the first of] the months of the year”—implying that the year should consist of months, and months only.

The moon is concealed each month, and remains invisible for approximately two days—for about one day before it is closest to the sun, and about one day after it is closest to the sun—after which it can be seen in the west in the evening. The night on which it is visible in the west marks the beginning of the month, and one counts from that day 29 days. If the moon is visible on the eve of the 30th, then the 30th day is Rosh Chodesh (“head of the month”); if not, then the 31st day is Rosh Chodesh, and the 30th day belongs to the previous month.

(Mishneh Torah, Laws of the Sanctification of the Moon)


Time is the first creation (see Sforno on Genesis 1:1); thus, the sanctification of time is the first mitzvah commanded to Israel.

(The Lubavitcher Rebbe)

The head of months (Exodus 12:2)

When G‑d chose His world, He established heads of months and years. When He chose Jacob and his sons, He established the head of the month of redemption.

(Midrash Rabbah)

Thus there are two “heads” to the Jewish year. The 1st of Tishrei (Rosh Hashanah), the day of the creation of man, is the head of the natural year—the year which the Jew shares with all of creation. The month of Nissan, marking the Exodus and the birth of Israel, is the head of a miraculous year: a dimension of time inhabited solely by the Jew, in which the miraculous—i.e., the power to transcend nature and norm—is the very stuff and substance of life.

(The Chassidic Masters)


On the tenth day of this month, they shall take to them every man a lamb. . . . You shall keep it until the 14th day of that month; and the whole assembly of the congregation of Israel shall slaughter it towards evening (12:3–6)

When G‑d told Moses to slaughter the paschal lamb, Moses said: “Master of the Universe! How can I possibly do this thing? Don’t You know the lamb is the Egyptian god? ‘Lo, if we sacrifice the abomination of the Egyptians before their eyes, will they not stone us?’” (Exodus 8:22)

Said G‑d: “By your life, Israel will not depart from here before they slaughter the Egyptian gods before their very eyes, so that I may teach them that their gods are really nothing at all.” This is what He actually did; for on that night He slew the Egyptian firstborn, and on that night the Israelites slaughtered their paschal lamb and ate it.

(Midrash Rabbah)

That year, the 10th of Nissan was a Shabbat; this is why the Shabbat before Passover is called Shabbat HaGadol (“The Great Shabbat”)—because a great miracle happened on that day. For when the children of Israel took their paschal lambs on that Shabbat, the Egyptian firstborn converged on them and asked them: “Why are you doing this?” They replied: “It is a passover sacrifice to G‑d, for He will kill the firstborn of Egypt.” The firstborn approached their fathers and Pharaoh to request that Israel be allowed to go, but they refused; so the firstborn waged war against them, killing many of them. Thus the verse (Psalms 136:10) proclaims: “[Offer thanks] to He who smote the Egyptian with their firstborn.”

(Tosafot to Talmud, Shabbat 87b)

I will pass through the land of Egypt this night, and will smite all the firstborn in the land of Egypt . . . and against all the gods of Egypt I will execute judgments: I am G‑d (12:12)

“I will pass”—I, and no angel; “I will smite”—I, and no seraph; “I will execute”—I, and no messenger; “I am G‑d”—I am He, and no other.

(Passover Haggadah)

And against all the gods of Egypt I will execute judgments (12:12)

Those that were of wood rotted; those that were of metal melted.


Seven days shall there be no leaven found in your houses (12:19)

On the eve of the fourteenth [of Nissan], a search is made for leaven by the light of a candle. . . . Why a candle? So that it can be brought into holes and chinks [in the wall].

(Talmud, Pesachim 2a, 8b)

There are other foods whose consumption is forbidden by the Torah; but leaven on Passover is forbidden to eat, benefit from in any way, or even keep in our possession. Usually, a forbidden substance becomes “nullified” if it mixes with a much greater quantity of permissible substances; of leaven, the Torah forbids even the slightest trace.

This is a reflection of what these “forbidden foods” represent on the spiritual level. Leaven is that which rises and inflates itself; in the human character, “leaven” is the trait of pride. While many negative traits can be useful in small, greatly diluted doses, the leaven of the soul must be utterly rejected. Thus the Talmud (Erachin 15b) states that G‑d says of the arrogant one, “I and he cannot dwell in the same world,” and Maimonides writes that while in all character traits one should follow the “golden mean,” the trait of pride one must avoid entirely, and follow the path of consummate humility. Like chametz on Passover, we must abandon any attempt to exploit it, and must totally eradicate it from every nook and cranny of our hearts.

(The Lubavitcher Rebbe)