Verses with the word ignorance in the Old Testament (12 verses):

Leviticus 4:2
Speak unto the children of Israel, saying, If a soul shall sin through ignorance against any of the commandments of the LORD concerning things which ought not to be done, and shall do against any of them:

Leviticus 4:13
And if the whole congregation of Israel sin through ignorance, and the thing be hid from the eyes of the assembly, and they have done somewhat against any of the commandments of the LORD concerning things which should not be done, and are guilty;

Leviticus 4:22
When a ruler hath sinned, and done somewhat through ignorance against any of the commandments of the LORD his God concerning things which should not be done, and is guilty;

Leviticus 4:27
And if any one of the common people sin through ignorance, while he doeth somewhat against any of the commandments of the LORD concerning things which ought not to be done, and be guilty;

Leviticus 5:15
If a soul commit a trespass, and sin through ignorance, in the holy things of the LORD; then he shall bring for his trespass unto the LORD a ram without blemish out of the flocks, with thy estimation by shekels of silver, after the shekel of the sanctuary, for a trespass offering.

Leviticus 5:18
And he shall bring a ram without blemish out of the flock, with thy estimation, for a trespass offering, unto the priest: and the priest shall make an atonement for him concerning his ignorance wherein he erred and wist it not, and it shall be forgiven him.

Numbers 15:24
Then it shall be, if ought be committed by ignorance without the knowledge of the congregation, that all the congregation shall offer one young bullock for a burnt offering, for a sweet savour unto the LORD, with his meat offering, and his drink offering, according to the manner, and one kid of the goats for a sin offering.

Numbers 15:25
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:

Numbers 15:26
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.

Numbers 15:27
And if any soul sin through ignorance, then he shall bring a she goat of the first year for a sin offering.

Numbers 15:28
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.

Numbers 15:29
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.