Please try to follow along. The First Commandment:
I am the LORD your God, who brought you out of the land of Egypt, out of the house of bondage. You shall have no other gods before me. You shall not make for yourself a graven image, or any likeness of anything that is in heaven above, or that is in the earth beneath, or that is in the water under the earth; you shall not bow down to them or serve them. It is written: "You shall worship the Lord your God and him only shall you serve."
The natural flow and breaks in the passage indicates how it should be understood. As noted previously...even Douay Rheims renders the breaks the same.
But then even with that aside....Rome has added to the "First Commandment".
In the CCC they've added to Exodus and Deuteronomy a passage from Matthew and call this the First Commandment.
The text in Exodus and Deuteronomy do not contain the passage from Matthew 4:10 which is a partial quote from Deuteronomy 6:13
13“You shall fear only the LORD your God; and you shall worship Him and swear by His name..[NASB]
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As written in the CCC:
I am the LORD your God, who brought you out of the land of Egypt, out of the house of bondage. You shall have no other gods before me. You shall not make for yourself a graven image, or any likeness of anything that is in heaven above, or that is in the earth beneath, or that is in the water under the earth; you shall not bow down to them or serve them.3
It is written: "You shall worship the Lord your God and him only shall you serve."4