29 Ye shall have one law for him that sinneth  through ignorance, both for him that is born among the children of Israel, and for the stranger that sojourneth among them.
29 One and the same law applies to everyone who sins unintentionally, whether a native-born Israelite or a foreigner residing among you.
29 You shall have one law for him who does anything unintentionally, for him who is native among the people of Israel and for the stranger who sojourns among them.
29 "The same standard holds for everyone who sins by mistake; the native-born Israelites and the foreigners go by the same rules.
29 You shall have one law for him who sins unintentionally, for him who is native-born among the children of Israel and for the stranger who dwells among them.
29 These same instructions apply both to native-born Israelites and to the foreigners living among you.
Matthew Henry's Commentary on Numbers 15:29
Commentary on Numbers 15:22-29
(Read Numbers 15:22-29)
Though ignorance will in a degree excuse, it will not justify those who might have known their Lord's will, yet did it not. David prayed to be cleansed from his secret faults, those sins which he himself was not aware of. Sins committed ignorantly, shall be forgiven through Christ the great Sacrifice, who, when he offered up himself once for all upon the cross, seemed to explain one part of the intention of his offering, in that prayer, Father, forgive them, for they know not what they do. It looked favourably upon the Gentiles, that this law of atoning for sins of ignorance, is expressly made to extend to those who were strangers to Israel.