9. Grudge not--rather "Murmur not"; "grumble not." The Greek is literally, "groan": a half-suppressed murmur of impatience and harsh judgment, not uttered aloud or freely. Having exhorted them to patience in bearing wrongs from the wicked, he now exhorts them to a forbearing spirit as to the offenses given by brethren. Christians, who bear the former patiently, sometimes are impatient at the latter, though much less grievous.
      lest . . . condemned--The best manuscript authorities read, "judged." James refers to Mt 7:1, "Judge not lest ye be judged." To "murmur against one another" is virtually to judge, and so to become liable to be judged.
      judge . . . before the door--referring to Mt 24:33. The Greek is the same in both passages, and so ought to be translated here as there, "doors," plural. The phrase means "near at hand" (Ge 4:7), which in the oldest interpretations [Targums of Jonathan and Jerusalem] is explained, "thy sin is reserved unto the judgment of the world to come." Compare "the everlasting doors" (Ps 24:7, whence He shall come forth). The Lord's coming to destroy Jerusalem is primarily referred to; and ultimately, His coming again visibly to judgment.

JFB.