The LORD told Moses what the people must do to make things right when they find out they have cheated the LORD without meaning to: If this happens, you must either sacrifice a ram that has nothing wrong with it or else pay the price of a ram with the official money used by the priests.
If you are poor and cannot afford to bring an animal, you may bring two doves or two pigeons. One of these will be a sacrifice to ask my forgiveness, and the other will be a sacrifice to please me.