"HaShem spoke to Moshe and to Aharon in the land of Egypt, saying, This month shall be to you the head of the months; to you it shall be the first of the months of the year." (Exodus 12:1-2)
Rosh Chodesh is the first day of each new month. It is designated by Torah as a holiday upon which certain offerings are made. The reckoning of each new month is required in order to accurately determine the Hebrew calendar and the days upon which holidays would begin and end. The new month was determined by the appearance of the new moon in the evening sky. In the days of the Holy Temple, two eyewitnesses to the appearance of the new moon were required to testify before the Great Sanhedrin in Jerusalem. They were cross-examined, and only after their testimony was verified beyond any doubt, the new month was declared.
Cross Examining the Witnesses
The cross examination conducted by the sages of the Sanhedrin was scrupulous, for two reasons: the new moon is often very faint just above the horizon and one could easily mistake a cloud for the new moon. In late second Temple times there were rivals to the sages of the Sanhedrin who might provide false testimony for the purpose of causing the sages to err.
The sages of the Sanhedrin knew when, where and how the new moon of each month would appear and would display before the witnesses pictures depicting the moon at different angles. If the witness pointed to a depiction that didn't correspond to the moon's actual appearance, his testimony was rejected.
In Tractate Rosh Hashanah (23b) we read that in light of the many new-moon witnesses who came each month, the Sages instituted the construction of Beit Ya’zek – a courtyard in Jerusalem where the witnesses could rest and be generously fed. This would encourage them to continue coming in the future.
New Moon Testimony on Shabbat
Witnesses of the new moon were allowed to travel on Shabbat and to be accompanied by helpers, if need be, who were permitted to do all that is necessary to protect and help them on their way, as stated specifically in the Mishna (Rosh Hashanah 1:9).
The reason Shabbat may be desecrated for this purpose is because Israel is commanded to declare the festivals at their appointed times, as written (Leviticus 23:4): “These are HaShem’s festivals that you must declare at their appointed times.” For Rosh Chodesh, as well, the kohanim must know what offering to bring that day, and so witnesses who saw the moon may set out for the Temple even on Shabbat.
An Incident in Lod
An incident is recounted in the Mishna (Rosh Hashanah 1:6): Forty pairs of new-moon witnesses, on their way to Jerusalem, arrived in Lod on the Sabbath. They were about to proceed along their way, in accordance with the law that such witnesses may travel on the Sabbath – but Rabbi Akiva stopped them, saying that certainly other witnesses had already testified and that their testimony was not necessary. Rabban Gamliel later told Rabbi Akiva that he had erred, because it would discourage future witnesses.
Rosh Chodesh Musaf Requirements
With the official announcement of the month, the kohanim would commence to performing the special additional (Musaf) offering to be made on Rosh Chodesh:
"And on the beginning of your months, you shall offer up a burnt offering to HaShem: two young bulls, one ram, and seven lambs in the first year, all unblemished. Three tenths of an ephah of fine flour as a meal offering, mixed with oil for each bull, and two tenths of an ephah of fine flour as a meal offering, mixed with oil for each ram. And one tenth of an ephah of fine flour mixed with oil as a meal offering for each lamb. A burnt offering with a spirit of satisfaction, a fire offering to HaShem. And their libations: a half of a hin for each bull, a third of a hin for each ram, and a quarter of a hin for each lamb wine; this is the burnt offering of each new month in its month, throughout the months of the year. And one young male goat for a sin offering to HaShem; it shall be offered up in addition to the continual burnt offering and its libation." (Numbers 28:11-15)
Blasts of the silver trumpets were sounded by the kohanim, as instructed by Torah:
"On the days of your rejoicing, on your festivals and on your new-moon celebrations, you shall blow on the trumpets for your ascent-offerings and your peace sacrifices, and it shall be a remembrance before your God; I am HaShem your G-d." (Numbers 10:10)
Nine blasts of the silver trumpets were sounded at the time of the additional Musaf offering, in addition to the trumpet blasts sounded on all other days of the year.
Song of the Day
The Levitical Choir, stationed on the duchan raised platform in the inner Temple courtyard, just inside the Nikanor Gates, facing the altar, would sing a song in honor of Rosh Chodesh. On Rosh Chodesh, which occurred on Shabbat, the song honoring Rosh Chodesh would replace the regular Shabbat song, in order to announce that today is Rosh Chodesh.
The Psalm sung by the Levites is not known with certainty. There are written sources, however, that suggest that Psalm 104, known as "Barchi Nafshi" (my soul, bless HaShem), was the song sung in the temple on Rosh Chodesh.
It is stated in Tractate Sofrim 19:7: "On the New Moon, groups of elders, Jerusalem notables, and students would assemble together from the time of the afternoon service onwards until the sun had set and the moon appeared in the night sky. It is necessary to say [after the ceremonial meal] in the benediction over the wine, ‘Blessed are You, HaShem our G-d, King of the universe, Who creates the fruit of the vine. Blessed are You, HaShem our G-d, King of the universe, Who has revealed the secret of the renewal of the moon, Who did instruct and teach us the [courses of] the seasons, New Moons and Festivals and Who did appoint men of understanding who determine the times [of the New Moons and Festivals]. You, our Rock, has weighed and calculated the minutest divisions of time whereby those New Moons and Festivals are determined, as it is written, Who appointed the moon for seasons; the sun knows his going down, and it also states, For as the new heavens and the new earth, which I will make’; and one concludes with ‘Blessed art You, HaShem, Who sanctifies Israel and the New Moons’. [Then one says,] ‘O give thanks unto HaShem for He is good; on this day we all in Jerusalem rejoice and are happy in the All-present. May Elijah the prophet soon come to us; may the king Messiah cause to spring forth in our days the [happy] time like the years when the Temple will be rebuilt, and may joyous occasions multiply in Israel’; and the people answer and say ‘Amen’. [The prayer is then continued,] ‘May good tidings multiply in Israel, may happy days multiply in Israel, may disciples of the Torah multiply in Israel. Consecrated is the New Moon, consecrated at the beginning of the month, consecrated in its proper time, consecrated in its intercalation, consecrated according to the Torah, consecrated according to the halachah, consecrated in the celestial regions, consecrated in the terrestrial regions, consecrated in the land of Israel, consecrated in Zion, consecrated in Jerusalem, consecrated in all the habitations of Israel, consecrated by the order of our Rabbis, consecrated in the House of Assembly. O give thanks unto HaShem for He is good’. Then [the reader] says, ‘You are all blessed’. After every benediction, moreover, [the reader] says, ‘O give thanks unto HaShem for He is good’, except after the benedictions of the Levites."
Performing the Rosh Chodesh Musaf Offering
On Rosh Chodesh, when the kohanim prepared the Musaf offering, (two bulls, a ram, and seven sheep - all burnt offerings, and a goat for sin offering), they would carry the butchered sections of the offerings up to the altar, but they would not immediately place them in the altar fire. Instead, they would first place them along the edge of the altar, that is, between the horns of the altar, as a way to further announce that this day is Rosh Chodesh, and another So they would go back there. Afterwards the kohanim would collect the pieces and place them on the fire.
Getting the Word Out
In order to spread the word of the new Moon across Israel and into the diaspora, torches were lit and waved from mountaintop to mountaintop, beginning just outside of Jerusalem and northward The torch on the furthest mountain would be seen by the residents of Pumbedita in Babylon, each of whom would light their own in response; the Mishna says the last torch would be waved up and down until all of Pumbedita would be lit up as if it were a great bonfire (Rosh Hashanah 2:3).
Among the mountains listed in the Mishna are Sartava, Gerofina, and Chavran; the Jerusalem Talmud adds others such as Geder in Transjordan. When Cutheans began to purposely disrupt the New Month declaration process by lighting their own torches at the wrong times, the torch system was retired.
Once the torch system was no longer used, horseback messengers were used instead to inform the Jews in far-off countries of the date of the new month. This had to be done with all speed, especially in the months of Tishrei and Nisan, when the Jews there had to prepare for their festival pilgrimage to Jerusalem and to make sure to arrive in time (Sukkot and Passover both begin on the 15th of the month).
At Home Offerings on Rosh Chodesh
In ancient times, it was customary in Israel to celebrate Rosh Chodesh by bringing whole offerings and conducting a family meal. This concept was recalled in the days of Saul and David, after the destruction of the Tabernacle of Shiloh. It was a historical period, in which Israelites were permitted to build an altar in their homes to perform the Rosh Chodesh offerings and eat them in purity. I Samuel, chapter 20 tells the story of a Rosh Chodesh feast held by King Saul, that David avoided attending, out of fear for his life.
Rosh Chodesh was also observed as a day of rest from work on the first month, and men and women would go to hear words of Torah from the sages on this day. A reference to this is made in II Kings 4:23: "And he said, 'Why are you going to him today; it is neither the New Moon nor the Sabbath.' And she said, "It's all right."