The following comment is inspired by Matthew 5:21,"Ye have heard that it was said of them of old time,Thou shalt not kill,and whosoever shall kill shall be in danger of the judgment," Killing
is done through out our lives,whether it's the killing of animals for food for us who eat meat,or the picking of fruits and vegetables to eat as a vegetarian,and many other things and life sources that we kill on a daily basis. Although this is not what Jesus
is refering to as he says that you have heard that it was said of them of old times,Thou shalt not kill, speaking about one of the commandments under the law and the killing of people,yet these things we kill. We don't have permission from God to just kill
people whenever we feel like it,or because we don't like them and have the means and will to do so. Killing just like seasons and every purpose under heaven have a time,as stated in Ecclesiastes 3:1-8,and it is justified by God when done in this order.