Leviticus 5:4-7

4or if any one swear rashly with his lips to do evil, or to do good, whatsoever it be that a man shall utter rashly with an oath, and it be hid from him; when he knoweth of it, then he shall be guilty in one of these things:

5and it shall be, when he shall be guilty in one of these things, that he shall confess that wherein he hath sinned:

6and he shall bring his guilt offering unto the LORD for his sin which he hath sinned, a female from the flock, a lamb or a goat, for a sin offering; and the priest shall make atonement for him as concerning his sin.

7And if his means suffice not for a lamb, then he shall bring his guilt offering for that wherein he hath sinned, two turtledoves, or two young pigeons, unto the LORD; one for a sin offering, and the other for a burnt offering.