Leviticus 5:9-11

New Revised Standard Version, Anglicised

⁹ He shall sprinkle some of the blood of the sin-offering on the side of the altar, while the rest of the blood shall be drained out at the base of the altar; it is a sin-offering. ¹⁰ And the second he shall offer for a burnt-offering according to the regulation. Thus the priest shall make atonement on your behalf for the sin that you have committed, and you shall be forgiven.

¹¹ But if you cannot afford two turtle-doves or two pigeons, you shall bring as your offering for the sin that you have committed one-tenth of an ephah of choice flour for a sin-offering; you shall not put oil on it or lay frankincense on it, for it is a sin-offering.