Numbers 15:14

a stranger a sojourner. For this word and the -homeborn," see on Numbers 9:14.

or whosoever be among you This appears to mean one who is residing in the land but has not been granted the definite status of a gêror -sojourner." Some, with less probability, understand it of a foreigner who is staying temporarily with Israelites.

throughout your generations i.e. at any future time.