The Gemoro (28a) tries to bring a Raaya from a case of a master hitting an Eved (when Yovel arrives) whom the Baraisa says is Potur, based on a posuk.
Why don't we say that since we need a posuk in this case, the master would otherwise be Chayav! (Or is the Gemoro saying that we learn from that posuk to Kol HaTorah?)
Kol Tuv,
Mark Bergman, Manchester, UK
The Otzar Mefarshei ha'Talmud mentions your question (in the name of the Teshuvos Eidus b'Yakov #115), and answers that without a Pasuk we would think that if the master could have merely hit this servant without wounding him, he would be Chayev Malkos if he indeed wounded him. The Pasuk teaches us that he is never Chayev Malkos for wounding this servant, even under these circumstances (the answer is from the Chidushei ha'Rim CM #4).
All the best,
Yaakov Montrose