Confession and Special Cases Requiring a Purification Offering
Leviticus can place ritual impurity, rash speech, and failure to testify in the same legal unit without saying they are morally identical. The chapter's big move is that recognized liability is confessed and addressed, not hidden.
Where this fits in the story: Explicitly continues Leviticus 4's purification-offering legislation.
Where Scripture takes it next: Hebrews 10 interprets the repeated purification/sacrificial system broadly.