Leviticus 15:15

15 The priest is to sacrifice them, the one for a sin offeringa and the other for a burnt offering. In this way he will make atonement before the LORD for the man because of his discharge.

Read Leviticus 15:15 Using Other Translations

And the priest shall offer them, the one for a sin offering, and the other for a burnt offering; and the priest shall make an atonement for him before the LORD for his issue.
And the priest shall use them, one for a sin offering and the other for a burnt offering. And the priest shall make atonement for him before the LORD for his discharge.
The priest will offer one bird for a sin offering and the other for a burnt offering. Through this process, the priest will purify the man before the LORD for his discharge.