Grudge not one against another - Margin, “groan, grieve.” The Greek word (στενάζω stenazō) means, “to sigh, to groan,” as of persons in distress, Romans 8:23; and then to sigh or groan through impatience, fretfulness, ill-humor; and hence “to murmur, to find fault, to complain.” The exact idea here is, not that of grudging in the sense of dissatisfaction with what others possess, or of being envious; it is that of being fretful and impatient - or, to use a common word which more exactly expresses the sense that of grumbling. This may arise from many causes; either because others have advantages which we have not, and we are discontented and unhappy, as if it were wrong in them to have such enjoyments; or because we, without reason, suppose they intend to slight and neglect us; or because we are ready to take offence at any little thing, and to “pick a quarrel” with them. There are some persons who are always grumbling. They have a sour, dissatisfied, discontented temper; they see no excellence in other persons; they are displeased that others are more prospered, honored, and beloved than they are themselves; they are always complaining of what others do, not because they are injured, but because others seem to them to be weak and foolish; they seem to feel that it becomes them to complain if everything is not done precisely as in their estimation it should be. It is needless to say that this spirit - the offspring of pride - will make any man lead a wretched life; and equally needless to say that it is wholly contrary to the spirit of the gospel. Compare Luke 3:14; Phi 4:11; 1 Timothy 6:8; Hebrews 13:5.
Lest ye be condemned - That is, for judging others with this spirit - for this spirit is in fact judging them. Compare the notes at Matthew 7:1.
Behold, the judge standeth before the door - The Lord Jesus, who is soon to come to judge the world. See James 5:8. He is, as it were, even now approaching the door - so near that he can hear all that you say.