But if the head is missing there will be no eggs anymore, because the body is dead. Similarly, if we reject the difficult part of the scriptures and obey the part we like, such an interpretation will not help us. We have to accept all the injunctions of the scripture as they are given, not only those that suit us. Christians take this commandment to be applicable to human beings, not to animals. There is killing, and there is murder.
Murder refers to human beings.
Killing means any kind of killing, and especially animal killing. If Jesus had meant simply the killing of humans, he would have used the word murder. He never spoke about man's relationship with other living entities, but only about his relationship with other human beings. We are not concerned with this or that testament but only with the words used in the commandments. If you want to interpret these words, that is something else.