Halakhah su Levitico 5:23

And one of these sins is one that illegally has money of a Jew in his hand, from the worth of a small coin and up - for example, he robs him or steals from him, or [money] that remained in his hand from a deposit that was deposited with him or because of a loan or a partnership. The principle of the matter is that [in a case] if he were to admit to him, he would be liable to pay by law, and the robbed or oppressed - or his inheritor or one that comes by his authority - sues him for it, but he denies it and swears falsely about it; when he repents and regrets his sin and returns the 'loot that is in his hand,' he is liable to bring this sacrifice that we said for his sin, besides the fifth that he is obligated to add on the principle and to give to the robbed, as it is stated (Leviticus 5:21), "A soul that sinned and misappropriated a misappropriation from God and denies his kinsman, etc." And Rabbi Akiva says, "What do we learn to say [from] 'a misappropriation from God?' Because any lender and borrower act only with witnesses, [therefore] when he denies, he only denies the witnesses; but one who borrows without witnesses and denies it, he denies the Third Party among them" - the Divine Presence - "That is why it states, 'and misappropriated a misappropriation from God and denies his kinsman, etc.'" (Sifra, Vayikra Dibbura d'Chovah, Chapter 22:4). And it is written after it (Leviticus 5 23-25), "And it shall be when he sins and is guilty" - meaning to say that he will repent, such that he takes responsibility for his own guilt - "and return the theft, etc. and he shall pay it from its principle, and a fifth shall he add upon it, etc. And he shall bring his guilt-offering to the Lord, a ram, etc." And this is what is called the guilt-offering of thefts; and this is from those that come whether for the inadvertent or for the volitional.

It is from the the roots of the commandment [that] a person not think that even though the matter of the prohibition of robbery is rectified by a positive commandment, as it is stated (Leviticus 5:23), "and return the theft" - that each one should go and rob what he wants from his fellow and imagine in his heart to say that when he has it and he return the theft, his iniquity will be atoned and he will be purified from it; and behold, it will be as if he never did it. And this would be an opening for sinners. Hence the Torah made known that even with the repayment with the addition of a fifth, he [still] needs a sacrifice for atonement, for his having sinned. And I have already written above (Sefer HaChinukh 123) about this matter, that nonetheless, it does not save him from having transgressed the will of his Creator. And it is a pity on his head that He transgressed the will of the Master of the Heavens, [even if] he sacrificed several [fat] sheep (peace-offerings) for burnt-offerings. And there I also wrote that the sacrifice and the principle impede the atonement, but the fifth does not impede [it].

The commandment of returning theft: That we were commanded to return the theft intact (Bava Kamma 66a) - meaning to say that if the thing itself that he robbed is with him and it has not changed in his possession, he is obligated to return it to the one robbed; and not take it for himself, and give its value to the one robbed - as it is stated (Leviticus 5:23), "and return the theft that he robbed." And we say in Bava Kamma 102a in the chapter [known as] HaGozel Batra, "The Rabbis learned, 'And return the theft that he robbed' - what do we learn to say [from] 'that he robbed?' That he return the intact item that he robbed." But if the theft changed in the possession of the robber, he is [only] obligated to repay its value, and he is exempted with that - even though the owners did not forsake it (Bava Kamma 66b). And what is a change that exempts from returning the theft? Like the change that he cannot reverse afterwards to its original state - for example, one who robs wood and burns it or cuts some of it up or digs holes in it; and so [too,] one who robs wool and dyes it or robs spun fabric and makes a garment out of it, and all that is similar to it. But one who robs boards of wood, even if he builds a box out of them - this is not a change that cannot revert to its original state. As behold, it is possible to dismantle them and they will go back [to being] boards as they had been. And therefore, he is obligated to return them intact. And so with all that is similar to this.