(Q) Derivation:
Lashes- Not Divided.
Payment- Divided.
(A1) We compare lashes to death. (Two verses have the word “rasha,” wicked, in them) Just as death cannot be divided, neither can lashes.
[1] “And it shall be that if the wicked one is liable to lashes.” (Devarim 25,2)
[2] “That he is wicked to die.” (Bemidbar 35,31)
(A2) The law of reciprocity itself teaches that punishments must be in full. The only reason payment is an exception is because money can combine. (to pay the victim; whereas lashes doesn’t benefit the victim)
(The reason the first opinion needed a verse, is because it maintains that reciprocity itself teaches that punishments combine)
*Connection: Explanation of current mishna*