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.
The trespass offering with a ram without blemish was one of many regular, systematic gifts required under the Levitical dispensation to set property apart and keep God's claims first. It was required of everyone rather than of a particular class and was proportioned to the amount possessed, so the larger the capital entrusted the more valuable the gift owed in return. It stood alongside the tithe, the ransom for the firstborn, the firstfruits of flocks and harvest, gleanings and field corners left for the poor, provision for the needy in the seventh year, sacrificial offerings, sin offerings, remission of debts every seventh year, hospitalities, gifts to the poor, and assessments.
Conscientious givers returned about one-third of their income for religious interests and the poor, besides special freewill offerings for the tabernacle and the temple. These requirements were made both for the givers' own good and to sustain God's service, reminding them of the Giver in almost every article. Their faithfulness, including whether vows had been performed, was preserved by stated examinations.