Ye have heard that it was said by them of old time, Thou shalt not kill; and whosoever shall kill shall be in danger of the judgment: Ye have heard that it was said by them of old time - τοις αρχαιοις, to or by the ancients. By the ancients, we may understand those who lived before the law, and those who lived under it; for murder was, in the most solemn manner, forbidden before, as well as under, the law, Genesis 9:5, Genesis 9:6.
But it is very likely that our Lord refers here merely to traditions and glosses relative to the ancient Mosaic ordinance; and such as, by their operation, rendered the primitive command of little or no effect. Murder from the beginning has been punished with death; and it is, probably, the only crime that should be punished with death. There is much reason to doubt, whether the punishment of death, inflicted for any other crime, is not in itself murder, whatever the authority may be that has instituted it. God, and the greatest legislators that have ever been in the universe, are of the same opinion. See Montesquieu, Blackstone, and the Marquis Beccaria, and the arguments and testimonies lately produced by Sir Samuel Romilly, in his motion for the amendment of the criminal laws of this kingdom. It is very remarkable, that the criminal code published by Joseph II., late emperor of Germany, though it consists of seventy-one capital crimes, has not death attached to any of them. Even murder, with all intention to rob, is punished only with "imprisonment for thirty years, to lie on the floor, to have no nourishment but bread and water, to be closely chained, and to be publicly whipped once a year, with less than one hundred lashes." See Colquhoun on the Police of the City of London, p. 272.