John 7:51

Doth our law judge a man?

(μη ο νομος ημων κρινε τον ανθρωπον;). Negative answer expected and "the man," not "a man." These exponents of the law (verse John 7:49) were really violating the law of criminal procedure (Exodus 23:1; Deuteronomy 1:16). Probably Nicodemus knew that his protest was useless, but he could at least show his colours and score the point of justice in Christ's behalf.Except it first hear from himself

(εαν μη ακουση πρωτον παρ' αυτου). Third-class negative condition with εαν μη and first aorist active subjunctive of ακουω. That is common justice in all law, to hear a man's side of the case ("from him," παρ' αυτου).And know what he doeth

(κα γνω τ ποιε). Continuation of the same condition with second aorist active subjunctive of γινωσκω with indirect question and present active indicative (τ ποιε). There was no legal answer to the point of Nicodemus.