Edward L. Greenstein’s contribution to The Decalogue in Jewish and Christian Tradition examines the rhetoric of the Ten Words. He raises the question of the order of the first two commandments. Traditions differ.
“In the later Jewish tradition, ‘I am YHWH your God’ is the first commandment, and ‘You are not to have any other gods’ and ‘You are not to make yourself a carved image’ are both part of the second. In the Samaritan, some early Jewish traditions, and Christian traditions, ‘I am YHWH your God’ is preliminary, and the first and second commandments are, respectively, ‘You are not to have any other gods’ and ‘You are not to make yourself a carved image.’ Many modern scholars, influenced by the comparison of biblical law to the structure of ancient Near Eastern vassal treaties, also tend to regard ‘I am YHWH your God’ as an introductory formula, neither a commandment in and of itself, nor an integral part of the commandment ‘You are not to have any other gods'” (8).
Rhetorically, none of these explains the form of the text. Greenstein points to “a formulaic parallel between the two prohibitions, ‘You are not to have any other gods’ and ‘You are not to make yourself a carved image.’ The second of these is followed by a motive clause: ‘for I, YHWH your God, am a jealous God.’ The reason not to make images of any other gods for purposes of worship is that YHWH, Israel’s god, is jealous and will not tolerate any rivals for Israel’s adoration” (8-9).
He points out that “the motive clause begins almost identically to the first line of the Ten Commandments: ‘I am YHWH your God.’ In line with this observation, the first line of the divine discourse should be regarded as the motive clause of the first commandment. That is, Israel must have no other god than YHWH because it was YHWH who liberated the Israelites from Egyptian servitude, and no other god” (9).
In short, motive clauses and prohibitions are arranged in a chiasm:
“A (motive) I am YHWH your God
B (prohibition) You are not to have any other gods
B’ (prohibition) You are not to make yourself a carved-image
A’ (motive) For I YHWH your God” (9).
Greenstein notes that there are parallels elsewhere in the Old Testament: “In Judg 6:8–10, YHWH is reported to say: I brought you out of Egypt, I am YHWH your God; thus you must not worship the gods of the Amorites (i.e. the Canaanites). And in Ps 81:10–11, the injunction ‘You shall have no foreign god’ is followed by the declaration: ‘I YHWH am your God who brought you out of the Land of Egypt’” (9).
Strictly, then, the first word begins with the prohibition “Thou shalt have no other gods before My face,” but the Ten Words actually begin with a motive clause, “I am Yahweh . . . who brought you from the land of Egypt, from the house of slavery.”