(Ibid. 20) "Righteousness, righteousness shall you pursue": Whence is it derived that if one leaves beth-din exonerated, he is not returned for incrimination (if something is later found in his disfavor)? From "righteousness shall you pursue."
If he leaves incriminated, whence is it derived that he is returned for exoneration (if something is later found in his favor)? From "righteousness, righteousness shall you pursue."
Variantly: "Righteousness, righteousness shall you pursue": Seek out the finest beth-din — the beth-din of R. Yochanan b. Zakkai in Beror Chayil; the beth-din of R. Eliezer in Lud.