Rashi on Genesis 42:34/רש"י על בראשית מ״ב:ל״ד

1ואת הארץ תסחרו AND YE SHALL TRAVEL IN THE LAND — It means literally, “ye may travel round the land”. All such words as סוחרים merchants, סחורה merchandise, are derived from this root סחר to go round, because the merchants travel round looking for merchandise.