Commentary on the Bible, by Adam Clarke, [1831], at sacred-texts.com
Concerning witnesses who, being adjured, refuse to tell the truth, Lev 5:1. Of those who contract defilement by touching unclean things or persons, Lev 5:2, Lev 5:3. Of those who bind themselves by vows or oaths, and do not fulfill them, Lev 5:4, Lev 5:5. The trespass-offering prescribed in such cases, a lamb or a kid, Lev 5:6; a turtle-dove or two young pigeons, Lev 5:7-10; or an ephah of fine flour with oil and frankincense, Lev 5:11-13. Other laws relative to trespasses, through ignorance in holy things, Lev 5:14-16. Of trespasses in things unknown, Lev 5:17-19.
If a soul sin - It is generally supposed that the case referred to here is that of a person who, being demanded by the civil magistrate to answer upon oath, refuses to tell what he knows concerning the subject; such a one shall bear his iniquity - shall be considered as guilty in the sight of God, of the transgression which he has endeavored to conceal, and must expect to be punished by him for hiding the iniquity to which he was privy, or suppressing the truth which, being discovered, would have led to the exculpation of the innocent, and the punishment of the guilty.
Any unclean thing - Either the dead body of a clean animal, or the living or dead carcass of any unclean creature. All such persons were to wash their clothes and themselves in clean water, and were considered as unclean till the evening, Lev 11:24-31. But if this had been neglected, they were obliged to bring a trespass-offering. What this meant, see in the notes on Leviticus 7 (note).
To do evil, or to do good - It is very likely that rash promises are here intended; for if a man vow to do an act that is evil, though it would be criminal to keep such an oath or vow, yet he is guilty because he made it, and therefore must offer the trespass-offering. If he neglect to do the good he has vowed, he is guilty, and must in both cases confess his iniquity, and bring his trespass-offering.
He shall confess that he hath sinned - Even restitution was not sufficient without this confession, because a man might make restitution without being much humbled; but the confession of sin has a direct tendency to humble the soul, and hence it is so frequently required in the Holy Scriptures, as without humiliation there can be no salvation.
If he be not able to bring a lamb - See the conclusion at Lev 1:16 (note).
But shall not divide it - See Clarke's note on Lev 1:16.
He shall offer the second for a burnt-offering - The pigeon for the burnt-offering was wholly consumed, it was the Lord's property; that for the sin-offering was the priest's property, and was to be eaten by him after its blood had been partly sprinkled on the side of the altar, and the rest poured out at the bottom of the altar. See also Lev 6:26.
Tenth part of an ephah - About three quarts. The ephah contained a little more than seven gallons and a half.
In the holy things of the Lord - This law seems to relate particularly to sacrilege, and defrauds in spiritual matters; such as the neglect to consecrate or redeem the firstborn, the withholding of the first-fruits, tithes, and such like; and, according to the rabbins, making any secular gain of Divine things, keeping back any part of the price of things dedicated to God, or withholding what man had vowed to pay. See a long list of these things in Ainsworth.
With thy estimation - The wrong done or the defraud committed should be estimated at the number of shekels it was worth, or for which it would sell. These the defrauder was to pay down, to which he was to add a fifth part more, and bring a ram without blemish for a sin-offering besides. There is an obscurity in the text, but this seems to be its meaning.
Shall make amends - Make restitution for the wrong he had done according to what is laid down in the preceding verse.
He hath certainly trespassed - And because he hath sinned, therefore he must bring a sacrifice. On no other ground shall he be accepted by the Lord. Reader, how dost thou stand in the sight of thy Maker? On the subject of this chapter it may be proper to make the following reflections. When the infinite purity and strict justice of God are considered, the exceeding breadth of his commandment, our slowness of heart to believe, and our comparatively cold performance of sacred duties, no wonder that there is sinfulness found in our holy things; and at what a low ebb must the Christian life be found when this is the case! This is a sore and degrading evil in the Church of God; but there is one even worse than this, that is, the strenuous endeavor of many religious people to reconcile their minds to this state of inexcusable imperfection, and defend it zealously, on the supposition that it is at once both unavoidable and useful - unavoidable, for they think they cannot live without it; and useful, because they suppose it tends to humble them! The more inward sin a man has, the more pride he will feel; the less, the more humility. A sense of God's infinite kindness to us, and our constant dependence on him, will ever keep the soul in the dust. Sin can never be necessary to the maintenance or extension of the Christian life, it is the thing which Jesus Christ came into the world to destroy; and his name is called Jesus or Savior because he saves his people from their sins. But how little of the spirit and influence of his Gospel is known in the world! He saves, unto the uttermost, them who come unto the Father through him. But alas! how few are thus saved! for they will not come unto him that they might have life. Should any Christian refuse to offer up the following prayer to God? "Almighty God, unto whom all hearts be open, and from whom no secrets are hid, cleanse the thoughts of our hearts by the inspiration of thy Holy Spirit, that we may perfectly love thee, and worthily magnify thy holy name, through Christ our Lord. Amen." - The Liturgy.