And when can be “If,” but the situation described should not be thought of as unlikely. Contemporary English Version does use an “if” clause in a helpful way: “If anyone who isn’t an Israelite wants to celebrate….” A stranger shall sojourn uses two words with the same root meaning, like “a sojourner will sojourn.” The noun stranger should be understood as a resident alien. The same word is used in verse 19, where Revised Standard Version uses “sojourner.” (See the discussion there and also at 2.22.) New Revised Standard Version corrects the idea of stranger by translating “an alien who resides with you.” Good News Translation is similar: “If a foreigner has settled among you.” With you is singular, but this is intended for the head of every family.

And would keep the passover is literally “and he makes passover [pesach].” The idea of would is suggested by the context, which is the same as “and wants to celebrate Passover” (Good News Translation). Passover to the LORD may mean either “Passover to honor the LORD” or “the LORD’s Passover” (New International Version), since the Hebrew form “to Yahweh” may also show possession. However, in some languages it will be possible to express this as “celebrate the festival that the LORD has instituted.”

Let all his males be circumcised, literally “be circumcised to him every male,” is a form indicating a command. All his males refers to all the men and boys in the family of the resident alien, as well as all his male servants. Contemporary English Version reflects this: “every man and boy in that family.” Good News Translation changes the passive voice to active and introduces “you” as the one [or, ones] who will perform the circumcision. The text, however, does not indicate who the agent should be, so it is better to retain the passive if possible, or else say “they shall circumcise,” with “they” being an unknown agent. However, in some languages that do not have the passive voice, one may use a word meaning “receive,” and say “they shall receive circumcision.” One may also use a term like “suffer” or “undergo” and translate, for example, “they shall undergo the cutting of the circumcision ceremony.” (See the comments on “circumcision” at 4.25-26.)

Then he refers only to the “resident alien,” who presumably was head of a household. The text does not indicate whether all his males were also permitted to participate, but the rite of circumcision would make this possible. He may come near means that he may participate, “be admitted” (New Jewish Publication Society’s Tanakh), or “join in” (Good News Translation, Contemporary English Version). And keep it, of course, refers to observing the Passover, or “the festival” (Good News Translation). He shall be as a native of the land means “he is to be treated as a native-born Israelite,” or “You are to consider him as….” As in verse 19, a native of the land does not refer to Egypt or to an Egyptian, but reflects the later settled Israelite community in Canaan.

But no uncircumcised person shall eat of it is added for emphasis. Eat of it refers to participating in the Passover meal. Note that Good News Translation places this clause at the beginning of the verse, connecting it with verse 47. This rearrangement is certainly possible and may suggest a more natural flow of thought. New Revised Standard Version, on the other hand, joins this clause with the following verse.

An alternative translation model for languages that do not use the passive voice is the following:

• If any foreigner [or, nonnative Israelite] wants to celebrate the Passover festival to honor the LORD, you must first circumcise every man and boy in his family. When this is done you can consider him as a native-born Israelite, and he may eat the meal. No man or boy who has not received circumcision may eat this meal.

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 .