John Gill's Bible Commentary Ver. 7. Then they shall confess their sin which they have done , etc.] The form of which confession, according to Fagius, was, O Lord, I am guilty of death, I have deserved to be stoned for this sin, or to be strangled for this trespass, or to be burnt for this crime, etc. and he shall recompense his trespass with the principal thereof, and add unto it the fifth [part] thereof ; paying the whole of whatsoever he had in any manner defrauded his neighbour of, to which he was to add a fifth part of that; that is, as Aben Ezra interprets it, it he confesses of himself, but if there are witnesses of it he must add two fifths, and some say a fifth of a fifth: and give [it] unto [him] against whom he hath trespassed ; as a satisfaction for the injury done him.
Matthew Henry Commentary
Verses 1-10 - The camp was to be cleansed. The purity of the church must be kept a carefully as the peace and order of it. Every polluted Israelite mus be separated. The wisdom from above is first pure, then peaceable. The greater profession of religion any house or family makes, the more the are obliged to put away iniquity far from them. If a man overreach of defraud his brother in any matter, it is a trespass against the Lord who strictly charges and commands us to do justly. What is to be don when a man's awakened conscience charges him with guilt of this kind though done long ago? He must confess his sin, confess it to God confess it to his neighbour, and take shame to himself; though it go against him to own himself in a lie, yet he must do it. Satisfactio must be made for the offence done to God, as well as for the los sustained by the neighbour; restitution in that case is not enoug without faith and repentance. While that which is wrongly gotten i knowingly kept, the guilt remains on the conscience, and is not don away by sacrifice or offering, prayers or tears; for it is the same ac of sin persisted in. This is the doctrine of right reason, and of the word of God. It detects hypocrites, and directs the tender conscienc to proper conduct, which, springing from faith in Christ, will make wa for inward peace.
Original Hebrew והתודו3034 את853 חטאתם2403 אשׁר834 עשׂו6213 והשׁיב7725 את853 אשׁמו817 בראשׁו7218 וחמישׁתו2549 יסף3254 עליו5921 ונתן5414 לאשׁר834 אשׁם׃816