Torah Temimah cites Bava Kamma.
“To whom it belongs” — one who steals from his fellow the value of a perutah and swears to him must pursue him even to Media.
Diyuk of “to whom it belongs” — pursue the owner even to a distant land.
Distance does not excuse personal return of the principal after shevuah and admission. Even a perutah’s worth must be carried after the owner as far as Media if necessary.