No one disputes that there are a total of 10 Commandments in number (Exodus 34:28; Deuteronomy 4:13; 10:4). They are listed in Exodus 20 and Deuteronomy 5. However, another method of numbering developed some time after the biblical canon was complete.
In the fifth century, Augustine (a Roman Catholic bishop of Hippo) selected a newer way of presenting the Ten Commandments, which became the preferred arrangement in the Catholic Church. This arrangement dropped the Second Commandment, divided the Tenth against coveting into two separate commands, one against coveting a neighbor's wife and another against coveting anything else belonging to a neighbor, thus renumbering the list of 10.
Yet the prohibition against coveting is given as one thought in one basic sentence. In contrast, having other gods and worshiping images are stated quite distinctly as two separate "thou shalt nots."
Notice that the apostle Paul expressed the commandment against coveting as a single commandment in the New Testament. "For the commandments, 'You shall not commit adultery,' 'You shall not murder,' 'You shall not steal,' 'You shall not bear false witness,' 'You shall not covet,' and if there is any other commandment, are all summed up in this saying, 'You shall love your neighbor as yourself'" (Romans 13:9; compare 7:7). Clearly one basic principle is involved, and one fundamental commandment governs it.
The most direct proof of this comes from comparing the listing of the Ten Commandments in Exodus and Deuteronomy, both books having been written by Moses. In Deuteronomy 5:21, the prohibition against coveting a neighbor's wife is given first, before the command against coveting a neighbor's house and other possessions.
But in Exodus 20:17 the proscription against coveting a neighbor's wife and house is mentioned in the opposite order. Obviously, Moses was not switching around the Ninth and Tenth Commandments. Rather, he understood these to be different aspects of the same Tenth Commandment.
So why was another arrangement of the commandments chosen? Augustine said that by this method the commandments were divided into the biblically significant numbers three and seven (claiming three commands on relating to God and seven on relating to neighbor—as opposed to four and six in the proper arrangement).
But there may be another reason that the three-and-seven arrangement arose in the first place—to allow the use of images in worship. The First Commandment forbids the worship of other gods. The Second Commandment forbids bowing down to, serving or using images in worship. By combining the Second Commandment with the First, it could appear that there is only one commandment against idolatry—and that the forbidding of images merely means that we are not to bow down to images of other gods. Yet, by having a separate commandment against images in worship, it is clear that what is forbidden is not just images of other gods, but of the true God as well.
For a more-complete understanding of the great spiritual principles behind all 10 of the commandments, please request our free booklet The Ten Commandments.