And in the beginnings of your months ye shall offer a burnt offering unto the LORD; two young bullocks, and one ram, seven lambs of the first year without spot;

Jamieson-Fausset-Brown Bible Commentary

11-15. And in the beginnings of your months ye shall offer a burnt offering unto the Lord-These were held as sacred festivals; and though not possessing the character of solemn feasts, they were distinguished by the blowing of trumpets over the sacrifices (Nu 10:10), by the suspension of all labor except the domestic occupations of women (Am 8:5), by the celebration of public worship (2Ki 4:23), and by social or family feasts (1Sa 20:5). These observations are not prescribed in the law though they obtained in the practice of a later time. The beginning of the month was known, not by astronomical calculations, but, according to Jewish writers, by the testimony of messengers appointed to watch the first visible appearance of the new moon; and then the fact was announced through the whole country by signal-fires kindled on the mountain tops. The new-moon festivals having been common among the heathen, it is probable that an important design of their institution in Israel was to give the minds of that people a better direction; and assuming this to have been one of the objects contemplated, it will account for one of the kids being offered unto the Lord (Nu 28:15), not unto the moon, as the Egyptians and Syrians did. The Sabbath and the new moon are frequently mentioned together.

Matthew Henry's Concise Commentary

28:9-15 Every sabbath day, beside the two lambs offered for the daily burnt-offering, there must be two more offered. This teaches us to double our devotions on sabbath days, for so the duty of the day requires. The sabbath rest is to be observed, in order more closely to apply ourselves to the sabbath work, which ought to fill up the sabbath time. The offerings in the new moons showed thankfulness for the renewing of earthly blessings: when we rejoice in the gifts of providence, we must make the sacrifice of Christ, that great gift of special grace, the fountain and spring-head of our joy. And the worship performed in the new moons is made typical of gospel solemnities, Isa 66:23. As the moon borrows light from the sun, and is renewed by its influences; so the church borrows her light from Jesus Christ, who is the Sun of righteousness, renewing the state of the church, especially under the gospel.