Leviticus 5:6-7

5:6 and he must bring his penalty for guilt to the Lord for his sin that he has committed, a female from the flock, whether a female sheep or a female goat, for a sin offering. So the priest will make atonement on his behalf for his sin.

5:7 “‘If he cannot afford an animal from the flock, he must bring his penalty for guilt for his sin that he has committed, two turtledoves or two young pigeons, to the Lord, one for a sin offering and one for a burnt offering.