There are three biblical versions of the Decalogue, but none of them contains a list of 10 items, never mind "commandments."
Finding the 10 commandments clearly listed in the Bible is a difficult, if not impossible, task. Not because they are cryptically hidden in some obscure, easy-to-overlook passage. Quite the contrary. It is rather because there are three different versions of what passes for them. One is found in Exodus (20:2-17), the second one in Deuteronomy (5:6-21), and the third one in Leviticus (19). To make matters worse, the three of them are organized and phrased quite differently. Getting a clean list of 10 items out of them is a delicate matter that requires exceptional hermeneutic and editorial skills.
Needless to say, depending on whether the reader is Jewish or Christian (even more, depending on the kind of Christian the reader is) these “commandments” will be numbered (and phrased, and interpreted, and organized) differently. Catholics, for example, consider “no other gods” plus “no graven images” to be the first commandment. Lutherans agree, but other Protestant Christians separate this commandment in two, “no graven images” being a commandment on its own.
The first two versions of the Decalogue (Exodus and Deuteronomy) are the ones modern readers are more acquainted with. Broadly speaking, they are relatively similar. But this doesn’t mean they don’t differ from each other in important aspects. For example, in the book of Exodus, the Sabbath command is a relatively “intellectual” or “spiritual” one. In Deuteronomy, it is clearly more “physical.” The original text of Exodus reads “to remember” (zkr, in Hebrew). Deuteronomy reads “to keep,” or “to actively preserve” (shmr).
There is surely a practical, “physical” aspect to remembering. One remembers by actively doing things that help preserve any given memory. But the “physical” difference between one text and the other appears to be more radical when we keep on reading. In Exodus, the justification for the Sabbath is the seven-day Creation story. “For in six days, Yahweh made heavens and earth, the sea, and all that is in them, and rested on the seventh day; therefore Yahweh blessed the sabbath day and hallowed it.” Even if the reader is willing to accept that an almighty God might need some rest after creating the universe, relating to a “tired God” might be quite challenging. How can the reader measure the degree of God’s tiredness? How are we to imagine God’s “day off”? How can we imitate his resting? Moreover, how are we to understand this rest, considering Genesis is not supposed to be read literally? As is to be expected, rabbinical (and Christian) traditions differ greatly on these points.
Deuteronomy, on the other hand, hinges on a particular aspect taken from the narrative of the exodus, the liberation of Israel from slavery under pharaoh: “you shall remember that you were a servant in the land of Egypt, and Yahweh your God brought you out thence with a mighty hand and an outstretched arm.” Actively preserving in one’s memory the severity and cruelty of enslaved, never-ending labor seems to add a very different (more immediate, less “metaphysical”) horizon to the commandment.
This is the greatest difference between these two versions, but it is certainly not the only one. Both Exodus and Deuteronomy read “honor your father and your mother,” but Deuteronomy adds “as Yahweh your God commanded you” while Exodus says “so that your days may be long in the land which the Lord your God gives you.” Deuteronomy includes long transitions between the commandments that follow “you shall not kill,” while Exodus goes straight from it into “you shall not commit adultery.” And, as Kristin Swenson explains in A Most Peculiar Book: The Inherent Strangeness of the Bible, “the coveting of wife and house are prioritized differently in the two versions (Exodus leads with ‘house,’ Deuteronomy with ‘wife’), and Deuteronomy adds ‘his field’ to the lot.”
Other differences depend on whether one makes “I am the Lord your God” the first commandment or not. In general, Christians say this is not really a command, since it requires no action whatsoever from the believer. Rabbinical tradition, on the other hand, argue it is not only a command but rather the commandment, to a great extent. If we are to consider the historical context in which these texts were written (one of competing gods, in which monotheism was still quite a rarity), recognizing the Lord as the One and Only God was an intentional, deliberate, even oftentimes risky act.
But, perhaps more revealing than a thorough list of differences, is the fact that nowhere in the original biblical texts (not on Exodus, not in Deuteronomy, not in Leviticus) is the word commandment used. Nowhere in the Bible are these regulations identified as such. The word the original text uses for what tradition has referred to as “commandments” is simply “word.” At the beginning of Exodus 20, the text simply reads “and God spoke all these words.” This is what Decalogue literally translates — not “10 commandments,” but “10 words.”
In an audience held in June 2018, Pope Francis explained the use of “word” instead of “commandment” highlights the difference between receiving an order and noticing that someone is trying to speak with us. It sets the mood for a dialogical relationship between the one who speaks and the one who listens: the texts comprising the Decalogue aim, first and foremost, at the establishment of a relationship between God and his people.
Francis explains his point by referring to the book of Genesis, which he understands to be in a typological relationship with these other biblical texts. He recalls how Satan deceived Adam and Eve precisely on this point: “He wants to convince them that God has forbidden them to eat the fruit of the tree of good and evil to keep them in submission. The challenge is precisely this: is the first rule that God gave to man the imposition of a despot who forbids and compels, or is it the care of a father who cares for his young and protects them from self-destruction? Is it a word or is it a command?”
In short, considering the original text says “word” and not “commandment” reminds us that, as Francis explains, “a command is a kind of communication that does not require dialogue. The word, on the other hand, is the essential means of relations as dialogue. A word is received, communication is given, and the commandments are words of God: God communicates Himself in these ten Words, and awaits our response.”