Sforno on Leviticus 20:25/ספורנו על ויקרא כ׳:כ״ה

1ולא תשקצו את נפשותיכם בבהמה ובעוף ובכל אשר תרמוש האדמה, from all kinds of “impure” living creatures אשר הבדלתי לכם, from the ritually “pure.”

2לטמא, in the sense that physically revolting creatures and especially ingesting them, will eventually contaminate the soul, the spiritual basis of the human being who has consumed them. This negative fallout is the result only of eating such creatures, not of carrying on trade involving them.