And you shall tell your son uses a word that means more than just tell. It means to report or announce something, or in this case, to “explain” (Good News Translation, Contemporary English Version). The you is singular, but your son includes “your sons” as well (Good News Translation). New Revised Standard Version even includes the daughters, with “your child.” So it is also possible to say “your children” (Contemporary English Version). On that day is ambiguous. It may refer to “the seventh day” in verse 6, as Contemporary English Version interprets it, or it may refer back to “this day” in verse 3, the day “When the festival begins,” as Good News Translation interprets it. The parallel references in 12.26 and 13.14 suggest that this same instruction is to be given whenever the children ask. Since the Hebrew is not explicit, it may be best to preserve the ambiguity, as in Translator’s Old Testament: “at that time.” Living Bible has “During those celebration days each year.”
It is because of is literally “on account of,” with the It is added for completeness. These are words to be spoken by the father to his children during the family observance of the festival, so New International Version has “I do this because of.” What the LORD did for me makes it a personal testimony. Good News Translation has “for you,” but this is because the direct quote has been changed to indirect speech. In many languages, however, direct speech will be preferred. Either way, the me or the “you” refers to the father who is to speak these words. When I came out of Egypt is literally “in my coming out of Egypt.” An alternative model for the final part of this verse is “I am celebrating like this because of the things that the LORD did for me when I came out of Egypt,” or even “The LORD helped me to escape from Egypt; so I am celebrating like this.”
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 .