John Gill Commentary Leviticus 6:4

"then it shall be, if he hath sinned, and is guilty, that he shall restore that which he took by robbery, or the thing which he hath gotten by oppression, or the deposit which was committed to him, or the lost thing which he found," — Leviticus 6:4 (ASV)

Then it shall be, because he has sinned and is guilty ,
&c.] Owns his guilt through remorse of conscience, and makes a confession of it; or otherwise, upon conviction, without such confession he was to pay double, see (Exodus 22:7–9) whereas, in this case it is only ordered,

that he shall restore that which he took violently away :
whether money, goods, or cattle:

or the thing which he has deceitfully gotten ;
by outwitting him, by extortion, by false accusation, or detention of wages:

or that which was delivered him to keep ;
in which he was unfaithful to his trust, be it what it will:

or the lost thing which he found ;
and denied he had it.