Commentaria in Exodum
1. AND THE LORD SAID:—These things were said in the first month, the month Nisan, that is, March, some days before the going out from Egypt and before the slaying of the firstborn; for this took place on the 15th day of the month, whereas here they are ordered to take the lamb on the tenth day of the same month, to be immolated on the 14th. Therefore these things were said by God and promulgated by Moses before the slaughter, and so before the tenth day. Hence, also, before the last conversation with Pharao, of which at the end of chap. 10 and the beginning of chap. 11; this is therefore a hysteron proteron; for Moses wished first to weave together the whole history of all the signs and plagues of Egypt, and then to narrate the going out of the Hebrews from Egypt, to which he prefaces the rite of the Phase, or paschal lamb, which was the symbol and token of the exodus and deliverance. Nisan corresponds to our March, or partly March, partly April. Josephus asserts that it is called Xanthicus by the Greeks and Pharmuthi by the Egyptians. For the Hebrews used lunar months, namely those which the moon describes by her course; but the course of the moon is not the passage through the Zodiac, for the moon traverses this in 27 days, nor the illumination of the zodiac (for the moon completes this in 28 days), but of the conjunction of the moon with the sun: for by counting the days that flow between one conjunction of the moon with the sun and the next, when the moon, left behind by the sun, begins to appear again, and makes the new moon, or novilunium, which is the first day of the month, there results the lunar month, which consists of 29 days and 12 hours besides, which 12 hours are joined together in alternate months so as to make up an entire day; for example, if 29 days be given to this month, the next will be given 30, the third again 29, the fourth 30, and so on in order. Hence it comes that the lunar year, consisting of twelve lunations or months, has but 354 days, and is shorter than the solar year by eleven days. Wherefore, to equalize the lunar year with the solar, they added a thirteenth month, now in the third year, now in the second, doubling the last month Adar, that is, February, which they therefore called Veadar, as if the second Adar; and that year was called embolismal, or excrescent; and so it came about that every 19 years the beginning of the solar and the lunar year was altogether the same; for with Adar doubled seven times, namely in the third, sixth, eighth, eleventh, fourteenth, seventeenth, and nineteenth years, the 209 days by which in the course of 19 years the solar year had outgrown the lunar were all brought back to one through these seven inserted months, as you will easily see if you work out the numbers and assign 30 days to the six months that are intercalated, but 29 days to the seventh, the last of the nineteenth year. So Bede, book On the Reckoning of Times, chap. 41, and Abulensis on Leviticus 21, Question 19. See Ribera, book 5 On the Temple, chap. 2.
Hence this is the Hebrew rule of embolism or intercalation: ter, ter, bis, ter, ter, ter, bis, as if to say: A month is to be intercalated in the third year; and in 19 years they inserted seven intercalary months; the embolism therefore fell in every third year, or sometimes the second; and thus they made their lunar years equal to the solar years, which other nations commonly used, in order to accommodate themselves and their times to them.
IT SHALL BE THE FIRST.—Therefore it had not been the first before; and so before the Phase, and before this deliverance of the Hebrews from Egypt, the first month was Tisri (a word which among the Chaldeans signifies beginning, says Josephus), which corresponds partly to our September, partly to October; and this is clearly gathered from chap. 23, verse 16, where the Lord, speaking of the feast of Tabernacles, which is celebrated in the seventh month, namely Tisri, says: “Thou shalt keep the solemnity at the end of the year”; but where the preceding year goes out and ends, there the following begins: therefore in Tisri, that is, in September, the year formerly ended and began. Hence also in chap. 34, verse 22, He calls the same solemnity that which comes “when the course of the year is returning, all things are laid up.” Hence also St. Jerome, on chap. 1 of Ezechiel, writes that the month of October is the first among all the Orientals.
Where note by the way: the Athenians began the year from the summer solstice, the Asiatics from the autumnal equinox, the Arabs and Damascenes from the vernal equinox, from which the Romans also, before Numa Pompilius, made the beginning of the year, defining the year by ten months only; but Numa added January and February: whence Ovid, Fasti, book 1:
He who follows Janus was the last of the old year.
After Numa, however, Julius Cæsar reduced the year to the reckoning which we now use, so that the year begins immediately after the winter solstice, namely from January. See Solinus, Polyhistor, book On Intercalary Days, chap. 1.
Here, then, at the going out of the Hebrews, the vulgar or common year begins to be distinguished from the sacred: the vulgar began from Tisri, or September, and served for the jubilee, as is plain from Leviticus 25, verses 9, 10, and for contracts and secular business, as Josephus teaches, book 1, Antiquities, chap. 4. But the sacred year, beginning from Nisan, that is, March (for in this month both Jews and Christians celebrate the Pasch), is here instituted and commanded, to the end that it may serve for the feasts, and that in memory of the salvation received and the deliverance from Egypt. For God willed the beginning of the year to be the beginning of His salvation and benefits: as after Noe and the flood He willed the rainbow to be the beginning of the new age, as a perpetual memorial of the covenant, mercy and divine grace, that He would never again overwhelm the world with a flood, so also now we begin the year from the circumcision of Christ, that is, from the beginning of His redemption.
Scripture, however, always uses the sacred year, as is plain from Zacharias 7, verse 5; 1 Machabees 4, 59; Esther chap. 2, verse 7. See Ribera on Aggeus 2, at the beginning.
Note the praises of the month Nisan. The first is that in it is celebrated the Pasch, the most celebrated feast. Secondly, in Nisan the Hebrews entered the land of promise, as is plain from Josue 4. Thirdly, in Nisan the world was created. Fourthly, in Nisan Christ was conceived, suffered and rose again. Fifthly, Nisan is called the month of new fruits, because about March in Palestine the crops, especially barley, begin to ripen. And these are the reasons why God willed the Phase to be celebrated in the spring, namely in Nisan. Hear St. Ambrose, On the Paschal Mystery, 2: “The Pasch,” he says, “is in spring the beginning of the year, the commencement of the first month, the renewal of the budding shoots, the night of cruel winter dispelled, the gladness of first spring restored. At this time God, the Maker of things visible and invisible, having fixed the earth and hung up the frame of heaven, made the day shine with the glow of the sun, and fashioned the sky,” etc.
You will ask, how can it be known and discerned which is the first month, or Nisan, in which the Pasch is to be celebrated?
I answer: the first and paschal month is that whose 14th day, or full moon, falls either upon the vernal equinox itself or first after it; whence it comes that the new moon of the first month cannot be before the eighth day of March, nor after the fifth day of April. The vernal equinox at the time of the Council of Nicæa fell on the 15th of March, where it also still has its place after the Gregorian correction of the Calendar; hence it comes that Nisan can never be wholly within March, but always runs on into April; and although it can sometimes happen that it is wholly outside March, yet it can never be wholly outside April; it can sometimes, however, be wholly within April; for the most part, however, it falls partly with March and partly with April, and sometimes runs on into May, namely if it be an embolismal year, that is, one increased by one month, Veadar, which precedes Nisan. So Pererius, from Clavius. Finally, hear St. Ambrose, Epistle the fourteenth day on the Lord’s Day; because we ought neither to fast on the Lord’s Day, nor, when the thirteenth moon falls on the Sabbath, to break the fast, which is above all to be observed on the day of Christ’s passion: the celebration of the Pasch is to be deferred to the other week. For the fifteenth moon follows, on which Christ suffered, and it will be the second day of the week; the third day also will be the sixteenth moon, on which the flesh of the Lord rested in the sepulchre; while the fourth day will be the seventeenth moon, on which the Lord rose again.”
IN THE MONTHS OF THE YEAR.—Note: The first month is Nisan, which corresponds to March; the second Jiar, which agrees with April; the third Sivan, with May; the fourth Tammuz, with June; the fifth Ab, with July; the sixth Elul, with August; the seventh Tisri, with September; the eighth Marchesvan, with October; the ninth Kisleu or Casleu, with November; the tenth Tebeth, with December; the eleventh Shebat, with January; the twelfth Adar, which corresponds to February.
Note that these names, Nisan, Jiar, Sivan and the rest, are not Hebrew but Chaldean, which the Hebrews received from the Chaldeans in the Babylonian captivity: whence they are found only in books written after the captivity, namely Zacharias, Esdras, Esther and the Machabees; for before they were called by numerical order, the first month, the second, the third, and so on, beginning from March; just as the Romans also call Quintilis, Sextilis, September, October, November the fifth, sixth, seventh, eighth, ninth month from March, which among the Romans too was formerly the first month of the year.
3. SPEAK YE TO THE WHOLE ASSEMBLY OF THE CHILDREN OF ISRAEL.—Speak to the ancients, that they themselves may severally proclaim the same thing to each one of the people; for Pharao would never have suffered the whole assembly of the Hebrews to be gathered together, and to gather this assembly secretly, without his knowing, was impossible. So in chap. 4, verse 29, Moses is said to have assembled the ancients of Israel, and yet presently, verse 30, he is said to have spoken to the people, namely what the ancients reported: for what he said to the ancients was reckoned as said to the whole people.