imputeth not. Forensic or legal righteousness. The N.T. righteousness is not negative, but positive, for the righteousness of One (Christ) is imputed or accounted to another, as it was to Abraham (Gen_15:6. Rom_4:13).
iniquity = sin in the nature, rather than breaches of the law in act = perverseness (never eradicated). Hebrew. 'avon.App-44.