(6) Speak to the Israelites: When a man or woman commits any wrong toward a fellow man, thus breaking faith with Adonai and that person realizes his guilt, (7) he shall confess the wrong that he has done. He shall make restitution in the principal amount and add one-fifth to it, giving it to him whom he has wronged.
איש או אשה, “man or woman, etc.” Nachmanides writes that the reason why the Torah mentions a woman here, although it is not usual for women to rob proselytes, is that we might have thought that if a woman had been guilty of this crime she would not have to do more than make restitution without adding the fifth mentioned here as a penalty; to make sure we do not err in this matter the Torah made sure that we understand that man and woman are subject to the same rules.
ואשמה הנפש ההיא, and that soul will be considered guilty. Inasmuch as that person is guilty of perjury he has caused damage to his very soul. The Torah suddenly switched to the use of the singular although previously it had spoken about people (pl) committing sins. Afterwards, when the Torah discusses the sinner confessing his sin it again uses the plural, i.e. והתודו. You will note that the Torah did not write that the soul of the sinner i.e. נפשו, nafsho, is guilty, but it writes הנפש ההיא, hanefesh hahee. This is a reference to the collective soul of the Jewish people which has become tarnished through one of its members committing perjury...
למעול מעל, “by committing treachery.” The Torah means that the guilty party not only stole, but swore an oath in the name of Hashem denying that he had done so....
.ואשמה הנפש ההיא, והתודו, ”and that soul shall be guilty, and confess;” Rabbi Natan claims ... that the first step in rehabilitation of the sinner must be his confession of having committed this trespass. (Sifri)
(ג) וחמישתו יוסף עליו. אם הוא מתודה מעצמו ואם יש עדים עליו יוסף שני חמישיות...
The singular verb here makes clear that he adds one-fifth only if he confesses on his own. But if witnesses testify against him, he must add two-fifths...
(א) איש או אשה כי יעשו מכל חטאות האדם למעול מעל ביי' וגומ'. בזה המקום בזאת הפרשה להסיר הרע מהמחנה אשר יביא למריבה וקטטה
He shall confess the wrong that he has done. This too involves banishing from the camp any evil behavior that might lead to quarreling or contention.