There shall be one law, literally “one torah will be,” refers to the various “regulations” (Good News Translation) for the Passover just listed. This means that “the same regulations apply” (Good News Translation) to both. (See the comment on torah at 13.9.) The native, or “citizen” (New Jewish Publication Society’s Tanakh), refers to the “Israelite by birth” (Translator’s Old Testament), and the stranger who sojourns among you refers to the “resident alien” or “foreigner” mentioned in verse 48. Among you, literally “in your midst,” is plural. Note that this verse concludes Yahweh’s words to Moses and Aaron that began in verse 43.

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 .