Thou shalt not commit adultery. — It will be seen that in this arrangement the seventh commandment precedes the sixth. The same arrangement is found in Mark 10:19; Luke 18:20, and James 2:11. On the other hand, the ordinary arrangement appears in Matthew 19:18. There can be no doubt that St. Paul followed an order that was found in the copies of the LXX. that he was in the habit of using. The famous Codex Vaticanus still presents the same order in Deuteronomy 5:17. In Exodus 20:13-15 it places the seventh commandment, first, then the eighth, then the sixth.
Related Commentaries of Romans 13:9
Romans 13:9
9 For this, Thou shalt not commit adultery, Thou shalt not kill, Thou shalt not steal, Thou shalt not bear false witness, Thou shalt not covet; and if there be any other commandment, it is briefly comprehended in this saying, namely, Thou shalt love thy neighbour as thyself.