Halakhah do Wyjścia 22:6

The commandment on the court to judge the case of an unpaid guardian: To judge the case of an unpaid guardian, as it is stated (Exodus 22:6), "If a man gives his neighbor silver or vessels to keep, etc." And the explanation that comes for it (Bava Metzia 94b) is that this section is stated about an unpaid guardian. And therefore it exempted him from [liability for] theft. And the understanding of "unpaid" is that the [guardian] did not receive any wage for his guardianship from the [owner].

He prohibited us - that we not steal money. And that is His, may He be exalted, saying, "You shall not steal" (Leviticus 19:11). And in the Mekhilta (Mekhilta d'Rabbi Yishmael 20:13:3): "'You shall not steal,' is the prohibition against stealing money." And one who transgresses this negative commandment is liable to pay that which is mentioned by Scripture - whether it is double-payment, four times or five times or just to return the principal. And in the Sifra (Sifra, Kedoshim, Section 2:1-2): "Because it is stated about stealing, 'He shall pay double' (Exodus 22:6), we know the punishment. From where [do we know] the prohibition? [Hence] we learn to say, 'You shall not steal.' [Even if only] to taunt [the owner]" - its explanation being, to annoy the owners and to hurt them; and to return it afterwards. "'You shall not steal' - even in order to pay four times or five times." And the regulations of this commandment have already been explained in the seventh [chapter] of [Bava] Kamma. (See Parashat Kedoshim; Mishneh Torah, Theft 1.)