And it shall be to you is literal, probably referring to “This observance” (Good News Translation), or “This celebration” (Contemporary English Version). Revised English Bible and New English Bible interpret this to mean “You must have,” adding the words, “the record of it,” that is, the record of “what the LORD did” (verse 8). The problem is whether to understand the sign on your hand literally or figuratively. (See the next paragraph.) Most translations take it figuratively, and translators are urged to follow this interpretation. In certain languages it will be necessary to provide an explicit goal for the event word “remind”; for example, one may say “When you celebrate this festival it will remind you of what the LORD did for you when you came out of Egypt. It will be like wearing….” An alternative model is “When you celebrate this festival it will be like wearing … because it will remind you….”
As a sign, literally “for a sign,” is the word ʾoth used in 3.12, where it means “proof,” and in 4.8, where it means “miracle.” Here, however, it means “a reminder,” a synonym for a memorial. (See the comment on ʾoth and “wonders” at 3.20.) On your hand and between your eyes have been interpreted literally by some Jews, who actually wear small leather pouches (“phylacteries”) strapped to their left arm and their forehead, and which contain words of scripture written on parchment. So Good News Translation has “like something tied on your hand or on your forehead.” Contemporary English Version has “This celebration will be like wearing a sign on your hand or on your forehead.” (See Deut 6.8 and 11.18.) Note that the and may be translated as or, as in verse 16 (so New Jerusalem Bible and Translator’s Old Testament).
That the law of the LORD refers to the torah of Yahweh, which is better understood in this context as the “instruction” (Durham) or “teaching of the LORD” (New Revised Standard Version, New Jewish Publication Society’s Tanakh, Contemporary English Version). This is the basic meaning of the Hebrew word, which is also one of several words for law. It later came to refer to the first five books of the Hebrew Bible as the authoritative collection of laws and stories for teaching the faith and history of Israel. May be in your mouth is literal and a bit ambiguous. It is clearer in New Revised Standard Version (and others) to say “may be on your lips,” for this suggests speaking or reciting the law. Good News Translation interprets this to mean “to continue to recite and study the Law of the LORD,” and this will be much clearer in many languages. However, it can also mean that the recitation is passing along the torah or teachings to others, in which case one may translate “to remind you to pass on the teachings of the LORD to your children” or “to remind you to recite the teachings of the LORD for others to hear.”
For with a strong hand refers to Yahweh’s “great power,” as in verse 3. (See also 3.19.) The LORD has brought you out of Egypt is literally “Yahweh caused you [singular] to go out from Egypt.”
Quoted with permission from Osborn, Noel D. and Hatton, Howard A. A Handbook on Exodus. (UBS Helps for Translators). New York: UBS, 1999. For this and other handbooks for translators see here .