136. They ask ben Zoma: Is it permissible FOR US to emasculate a dog? He replies, "Neither shall you do thus in your land" (Vayikra 22:24). THE MEANING IS, you shall not do thus to anything in your land, EVEN TO A DOG, for as the world needs one thing, it needs another, MEANING THERE IS NOTHING IN THE WORLD THAT IS NOT NEEDED. Therefore, we learned that "and, behold, it was very good" (Beresheet 1:31) refers to the Angel of Death that he should not be blotted from the world, BECAUSE the world needs him. Even though it is written about him, THE ANGEL OF DEATH, "Yea, the dogs are greedy, they never have enough..." (Yeshayah 56:11). IT IS NOT GOOD that they should become extinct from the world. Everything is needed, BOTH good and bad.