Numbers 15:25-28 (KJV)
25 And the priest shall make an atonement for all the congregation of the children of Israel, and it shall be forgiven them; for it is ignorance: and they shall bring their offering, a sacrifice made by fire unto the Lord, and their sin offering before the Lord, for their ignorance:
26 And it shall be forgiven all the congregation of the children of Israel, and the stranger that sojourneth among them; seeing all the people were in ignorance.
27 And if any soul sin through ignorance, then he shall bring a she goat of the first year for a sin offering.
28 And the priest shall make an atonement for the soul that sinneth ignorantly, when he sinneth by ignorance before the Lord, to make an atonement for him; and it shall be forgiven him.