And the priest shall offer the one [for] a sin offering
As in the case of a man that had an issue, the offerings of one and the other were the same and for the same purpose; (See Gill on Leviticus 15:15); there being a legal uncleanness in their case, atonement must be made by sacrifice, typical of the atonement of Christ, who by himself has purged our sins. The design of these several laws concerning uncleanness by issues, was to set forth the filthiness of sin arising from the corruption of human nature; particularly the pollution of fleshly lusts, and the necessity of purification from them by the grace of God, and blood of Christ, and of holiness of heart and life, in order to a near approach to God, particularly in public worship, as the next words suggest.
The Brenton translation of the Septuagint is in the public domain.