R. Yehudah says: It is written here "you shall have no pity," and elsewhere (Ibid. 19:21) "You shall have no pity." Just as there, monetary compensation (is indicated), here, too, monetary compensation (is understood).
(Devarim 25:13) "There shall not be unto you in your pocket a stone and a stone, great and small": I might think that one should not make a litra, a half-litra, or a quarter-litra weight; it is, therefore, written "great and small" — a great weight which "falsifies" the small, i.e., he should not take with the great weight and return with the small, (giving the impression that he is using the same weight).