Positive commandment · Mitzvat Aseh #194 of 613
To return a stolen object
להשיב את הגזל
The verse · Vayikra 5:23
וְהָיָה כִּי־יֶחֱטָא וְאָשֵׁם וְהֵשִׁיב אֶת־הַגְּזֵלָה אֲשֶׁר גָּזָל אוֹ אֶת־הָעֹשֶׁק אֲשֶׁר עָשָׁק אוֹ אֶת־הַפִּקָּדוֹן אֲשֶׁר הׇפְקַד אִתּוֹ אוֹ אֶת־הָאֲבֵדָה אֲשֶׁר מָצָא
“then it shall be, because he has sinned, and is guilty, that he shall restore that which he took violently away, or the thing which he has deceitfully acquired, or that which was delivered him to keep, or the lost thing which he found,”
The Rambam’s words
To return a stolen object, as [Leviticus 5:23] states: "And he shall return the object which he stole."
להשיב את הגזל, שנאמר: "והשיב את הגזילה אשר גזל" (ויקרא ה,כג).
Why · Sefer HaChinuch #130
Returning theft
“The root of the commandment is well-known.”
Who & when
“And [it] is practiced in all places and at all times by males and females.”
Where in the Mishneh Torah
Hilchot Robbery and Lost Property הלכות גזילה ואבידה