Let no corrupt communication... — The word rendered “corrupt,” is a strong word, signifying “rotten”; used in Matthew 7:17-18, and elsewhere in the literal sense, here alone in the metaphorical. By the corrupt word, probably, here is meant especially the foul word, which is rotten in itself, and spreads rottenness in others.
The use of edifying. — This is a mistranslation, by inversion, of a difficult expression, “the building up of the need” — that is, the supplying by suggestion of good the peculiar “need” or defect of the hearer’s spiritual state. Perhaps, as before, the word “good” may be taken for gracious and full of sympathy, noting by the quick insight of love what each man’s need is, and hastening to speak accordingly, so as to “give grace” or blessing to meet that peculiar need. The same use of the word “grace” is found in 2 Corinthians 1:15 (“that ye might have a second benefit”). The same idea is found in 1 Thessalonians 3:10, “to perfect that which is lacking in your faith.”
Here again we have a similar treatment of moral duty. The corrupt word is forbidden, not because it defiles the speaker’s own soul, and is an offence in the pure eyes of God, but because it is a sin against others, pulling down instead of building them up, and aggravating, instead of supplying, their moral defects. Like the falsehood, and wrath, and dishonesty, forbidden above, it sins against the unity of all in God.