Heb. tamim, “complete,” “perfect.” See on Ps. 15:2, where the same word is translated “uprightly.” In Job 1:1 a related word, tam, is rendered “perfect.” Although a very strong assertion, David seems, in the light of v. 22, to mean that he endeavors to avoid all known sin. Consider David’s testimony of himself (1 Sam. 26:23, 24), God’s testimony (1 Kings 14:8), and the testimony of the historian (1 Kings 15:5). For David’s claim to innocence from known sin to be true, the psalm must have been written before his sin with Bath-sheba and his crime of ordering the death of Uriah.