And if ye have erred. He teaches by what kind of sacrifice the sins of the whole people or of each individual are to be expiated, although he enumerates only two of the four classes which are mentioned in Leviticus; for a special atonement is there enjoined both on the priest and the ruler. But neither is the ceremony of sacrificing here described, since Moses only wished to refresh their memories by the way as to the manner in which, either publicly or privately, they were to be reconciled to God. This word "error," as we have said, extends to incogitancy, which partakes of contempt of God, and arises from too great security, when men inconsiderately fall into the sins to which their lusts invite them; for deliberate impiety is afterwards brought into contrast with error, when men designedly rush into violations of the law. But since nothing is more easy than for men to err, this remedy was most necessary, lest they who had sinned should fall into despair. Lest, then, the people or private individuals, when they saw their guilt, should despair of pardon and throw away the pursuit of holiness, God anticipates them, and shews them by what means He is to be propitiated, so that the sins which had occurred should not interrupt His service. Since, however, Moses here only repeats what has already been explained, there is no need of dwelling largely upon it, except that in one point he seems to deliver a law different from the former one; for he there commands two bullocks to be slain for the reconciliation of the people, [1] the one as a burnt-offering, the other as a sin-offering; yet, if the second were not easily obtained, the permission was given to substitute a goat. In Leviticus, therefore, the regular and perfect rite was delivered; the permissive alteration is only added here; nor does Moses contradict himself, though, for the sake of brevity, he only refers to one of the two modes. At the end a clearer explanation is subjoined, viz., that the same law should be common to all, since it was by no means expedient to introduce any diversity.

Footnotes

1 - "This law differs from Leviticus 4:13, 14. Outram thinks the bullock was to be offered under that law when the whole congregation of Israel, though in other respects retaining their own rites and following the worship of the true God, yet, led away by one common error, transgressed, without knowing it, some prohibitory precept. The kid for a sin-offering, accompanied with a bullock for a burnt-offering, (see ver. 24,) Outram says he apprehends to have been required when the people, neglecting their ancient rites and unmindful of the divine laws, (which often happened under wicked kings,) were seduced into strange worship. What is recorded in 2 Chronicles 28:24, 29:3, 21, 24, Outram thinks adds much probability to his opinion. See Outram, D. 1, ch. 14, Section 2." -- Brightwell in loco.

The heavy punishments which had already overtaken the people might naturally give rise to apprehensions for the future, especially in view of the fact that on the approaching entrance into Canaan the complete observance of the Law in all its details would become imperative on them. To meet such apprehensions a distinction is emphatically drawn between sins of ignorance (Leviticus 4:13 ff) and those of presumption Numbers 15:30-31. The passage deals separately with imperfections of obedience which would be regarded as attaching to the whole nation Numbers 15:22-26, and those of individuals Numbers 15:27-30.

And if ye (f) have erred, and not observed all these commandments, which the LORD hath spoken unto Moses,
(f) By oversight or ignorance, read (Leviticus 4:2, Leviticus 4:13).

And if ye have erred,.... Gone astray from the law of God, and any of its precepts; every sin is an error, a missing of the mark, a wandering from the way of God's commandments. Jarchi, and the Jews in general, interpret this of idolatry, but it rather respects any deviation from the law, moral or ceremonial, especially the latter:
and not observed all these commandments which the Lord hath spoken unto Moses; in this chapter, more particularly concerning the meat offerings and drink offerings, and the quantity of them, to be brought along with their burnt offerings and peace offerings, and concerning the cake of the first dough to be heaved before the Lord and given to the priest.

Though ignorance will in a degree excuse, it will not justify those who might have known their Lord's will, yet did it not. David prayed to be cleansed from his secret faults, those sins which he himself was not aware of. Sins committed ignorantly, shall be forgiven through Christ the great Sacrifice, who, when he offered up himself once for all upon the cross, seemed to explain one part of the intention of his offering, in that prayer, Father, forgive them, for they know not what they do. It looked favourably upon the Gentiles, that this law of atoning for sins of ignorance, is expressly made to extend to those who were strangers to Israel.

if ye have erred, and not observed all these commandments, &c.--respecting the performance of divine worship, and the rites and ceremonies that constitute the holy service. The law relates only to any omission and consequently is quite different from that laid down in Leviticus 4:13, which implies a transgression or positive neglect of some observances required. This law relates to private parties or individual tribes; that to the whole congregation of Israel.

All these commandments - Those now spoken of, which concern the outward service of God, or the rites or ceremonies belonging to it. And herein principally this law may seem to differ from that Leviticus 4:13, which speaks of some positive miscarriage, or doing that which ought not to have been done, about the holy things of God; whereas this speaks only of an omission of something which ought to have been done about holy ceremonies.