Since the Ten Commandments (or in Hebrew Ten Statements) are situated in a long passage in both Exodus (cap. 20) and Deutronomy (cap. 5) but not delimited or numbered (that is, separated in the text itself), they must be semantically extracted by the reader. As such, there have come down, in the Christian tradition at least, two main ways of numbering them. One that considers having other gods and having idols as one and the same Commandment, and one that considers coveting one's wife and coveting one's neighbour's property, separate, and the other that the commandment against idolatry and against making idols specifically are actually two separate but related commandments, but blend the coveting commandments into one instead. But both views take liberties (as it were) with how they instantiate the coveting commandment (and others).1
Here is 'the whole first commandment,' according to the first view:
I am the Lord your God who brought you out of the land of Egypt from the house of servitude. You shall have no other gods before me. You shall not make for yourselves any graven image or any likeness of anything in heaven above or on earth below, or in the waters beneath the earth. You shall not bow before them or serve them: for I the Lord, your God, am jealous God, bringing the iniquity of the fathers upon the sons, down to the third and the forth generation of those that hate me: but showing kindness to thousands of those that love me, and keep my ordinances.
Only the bold portion is considered a separate commandment, and the rest is surrounding explanation.
According to the second view, there are two separate commandments:
I am the Lord your God who brought you out of the land of Egypt from the house of servitude. You shall have no other gods before me.
You shall not make for yourselves any graven image or any likeness of anything in heaven above or on earth below, or in the waters beneath the earth. You shall not bow before them or serve them: for I the Lord, your God, am jealous God, bringing the iniquity of the fathers upon the sons, down to the third and the forth generation of those that hate me: but showing kindness to thousands of those that love me, and keep my ordinances.
The first view is, for example, the Catholic view, and the second view is taken by Protestants, for example.
For me personally, it does inescapably seem to be redundant if taken as a separate commandment; but both lists also imply the alternative list, so enither are invalid as such. The point is no list is given, only a passage. While the text declares that the list is that of ten commandments, it doesn't tell us what constitutes each or its limits. And even then, we still summarize in different ways, such as, according to the second view, merging the things coveted into coveting in general. Or in both views, bearing false witness against your neighbour, to bearing false witness generally. Further than this most Christians will extrapolate from the prohibition of adultery, per the words of Jesus Himself, that all fornication of any kind is forbidden by the spirit of this commandment (if not the letter).
1 Some commit the fallacy of who have only one commandment for coveting of making wives out to be yet another form of property along with cattle. But this is fallacious, it assumes that because both spouses and property are "had" ("my wife" "my husband" "my property"), this means they are had in the same sense or valued equally. Both wives and property are indeed coveted, but this doesn't mean they are the same thing!