Leviticus 5:7-8

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.

8He must bring them to the priest and present first the one that is for a sin offering. The priest must pinch its head at the nape of its neck, but must not sever the head from the body.