Leviticus 5:4-7

4Or if any one swear, talking rashly with the lips, to do evil or to do good, in everything that a man shall say rashly with an oath, and it be hid from him, when he knoweth [it], then is he guilty in one of these.

5And it shall be, when he shall be guilty in one of these, that he shall confess wherein he hath sinned;

6and he shall bring his trespass-offering to Jehovah for his sin which he hath sinned, a female from the small cattle, a sheep or doe goat, for a sin-offering; and the priest shall make atonement for him [to cleanse him] from his sin.

7And if his hand be not able to bring what is so much as a sheep, then he shall bring for his trespass which he hath sinned two turtle-doves or two young pigeons, to Jehovah; one for a sin-offering, and the other for a burnt-offering.