Pronouncing - Idly speaking Psalm 106:33. The reference is to an oath to do something uttered in recklessness or passion and forgotten as soon as uttered.

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.

Or if a soul swear,.... A rash or vain oath:

pronouncing with his lips; not in his heart, as Jarchi notes; not saying within himself that he would do this, or that, or the other thing, but expressing his oath plainly and distinctly, with an audible voice:

to do good, or to do evil; which was either impossible or unlawful for him to do; whether the good or evil he swears to do is to himself or to another; whether he swears to do good to himself, and evil to another, or, good to another, and evil to himself, see Psalm 15:4. The Targum of Jonathan paraphrases it,"whatsoever a man expresses, whether of anything present or future;''as if he swears he has done such and such a thing, whether good or evil; or that he will do it, be it what it will, and it is not in the power of his hands to do it, or, if he did it, it would be doing a wrong thing:

whatsoever it be that a man shall pronounce with an oath, and it be hid from him; he has forgot that he ever swore such an oath:

and when he knoweth of it, then he shall be guilty in one of these; when he is told of it, and it is made clearly to appear to him, that he did at such a time, and in such a place, deliver out a rash oath concerning this, or the other thing, then he shall be chargeable with guilt in one of these; either in rashly swearing to do good when it was not in his power, or to do evil, which would have been unlawful. The Targum of Jonathan is,"if he knows that he has falsified, and repents not, he is guilty.''

The third was, if any one should "swear to prate with the lips," i.e., swear in idle, empty words of the lips, - "to do good or evil," i.e., that he would do anything whatever (Numbers 24:13; Isaiah 41:23), - "with regard to all that he speaks idly with an oath," i.e., if it related to something which a man had affirmed with an oath in thoughtless conversation, - "and it is hidden from him," i.e., if he did not reflect that he might commit sin by such thoughtless swearing, and if he perceived it afterwards and discovered his sin, and had incurred guilt with regard to one of the things which he had thoughtlessly sworn.

Or if a soul {b} swear, pronouncing with his lips to do evil, or to do good, whatsoever it be that a man shall pronounce with an oath, and it be hid from him; when he knoweth of it, then he shall be guilty in one of these.

(b) Or, vow rashly without just examination of the circumstances, and not knowing what shall be the issue of the same.

5:4 If a soul swear - Rashly, without consideration either of God's law, or his own power or right, as David did, 1Sam 25:22. To do evil - To himself, to punish himself either in his body, or estate, or something else which is dear to him. Or rather to his neighbour. And it be hid from him - That is, he did not know, or not consider, that what he swore to do, was or would be impossible, or unlawful: When he discovers it to be so, either by his own consideration, or by information from others, whether it was good or evil which he swore to do.

Le 5:4-19. For Swearing.

4. if a soul swear-a rash oath, without duly considering the nature and consequences of the oath, perhaps inconsiderately binding himself to do anything wrong, or neglecting to perform a vow to do something good. In all such cases a person might have transgressed one of the divine commandments unwittingly, and have been afterwards brought to a sense of his delinquency.

5:1-13 The offences here noticed are, 1. A man's concealing the truth, when he was sworn as a witness to speak the truth, the whole truth, and nothing but the truth. If, in such a case, for fear of offending one that has been his friend, or may be his enemy, a man refuses to give evidence, or gives it but in part, he shall bear his iniquity. And that is a heavy burden, which, if some course be not taken to get it removed, will sink a man to hell. Let all that are called at any time to be witnesses, think of this law, and be free and open in their evidence, and take heed of prevaricating. An oath of the Lord is a sacred thing, not to be trifled with. 2. A man's touching any thing that was ceremonially unclean. Though his touching the unclean thing only made him ceremonially defiled, yet neglecting to wash himself according to the law, was either carelessness or contempt, and contracted moral guilt. As soon as God, by his Spirit, convinces our consciences of any sin or duty, we must follow the conviction, as not ashamed to own our former mistake. 3. Rash swearing, that a man will do or not do such a thing. As if the performance of his oath afterward prove unlawful, or what cannot be done. Wisdom and watchfulness beforehand would prevent these difficulties. In these cases the offender must confess his sin, and bring his offering; but the offering was not accepted, unless accompanied with confession and humble prayer for pardon. The confession must be particular; that he hath sinned in that thing. Deceit lies in generals; many will own they have sinned, for that all must own; but their sins in any one particular they are unwilling to allow. The way to be assured of pardon, and armed against sin for the future, is to confess the exact truth. If any were very poor, they might bring some flour, and that should be accepted. Thus the expense of the sin-offering was brought lower than any other, to teach that no man's poverty shall ever bar the way of his pardon. If the sinner brought two doves, one was to be offered for a sin-offering, and the other for a burnt-offering. We must first see that our peace be made with God, and then we may expect that our services for his glory will be accepted by him. To show the loathsomeness of sin, the flour, when offered, must not be made grateful to the taste by oil, or to the smell by frankincense. God, by these sacrifices, spoke comfort to those who had offended, that they might not despair, nor pine away in their sins. Likewise caution not to offend any more, remembering how expensive and troublesome it was to make atonement.