For he that said, Do not commit adultery, said also, Do not kill. Now if thou commit no adultery, yet if thou kill, thou art become a transgressor of the law.
He is One who gave the whole law; therefore they who violate His will in one point, violate it all (Bengel). The law and its Author have a complete unity.
Adultery ... kill - selected as the most glaring violations of duty toward one's neighbour.