Commandments, the Ten means in the bible: Ex. 34:28; Deut. 10:4. These Hebrew names are the “Ten Words” in Hebrew, hence their Greek name Decalogue. These are sometimes called the Covenant Deut. 9:9, or the Testimony Ex. 25:21. Ex. describes the giving by God of the Ten Commandments to Moses and Israel through him. 19:16-20:21; 32:15-19; 34:1. These were written on two stone tables, and placed inside the Ark. The Ark became the Ark of the Covenant Num. 10:33. The way the commandments were broken down into ten has caused disagreement. Following the lead of St. Augustine’s example, the Roman Church unites the two we already know and splits the second into two. The following is a quote from Our Lord: Deut. 6:4-5, and Lev. 6:4-5 and Lev. 22:37-39. For their true meaning, we need to read them under the guidance of the Sermon on Mount. See also Mark 2:27 and Matt. For the interpretations of 4th and 5th, see 15:4-6. It is clear that these are meant to guide our thoughts and our desires.
(in Bible Dictionary)