Matthew Henry commentary on Proverbs 12:15-16
Embedded KJV/source Scripture
17 He that speaketh truth sheweth forth righteousness: but a false witness deceit.
Here is, 1. A faithful witness commended for an honest man. He that makes conscience of speaking truth, and representing every thing fairly, to the best of his knowledge, whether in judgment or in common conversation, whether he be upon his oath or no, he shows forth righteousness; he makes it to appear that he is governed and actuated by the principles and laws of righteousness, and he promotes justice by doing honour to it and serving the administration of it. 2. A false witness condemned for a cheat; he shows forth deceit, not only how little conscience he makes of deceiving those he deals with, but how much pleasure he takes in it, and that he is possessed by a lying spirit, Jer. ix. 3-5 . We are all concerned to possess ourselves with a dread and detestation of the sin of lying ( Ps. cxix. 163 ) and with a reigning principle of honesty.
Embedded KJV/source Scripture
18 There is that speaketh like the piercings of a sword: but the tongue of the wise is health.
The tongue is death or life, poison or medicine, as it is used. 1. There are words that are cutting and killing, that are like the piercings of a sword. Opprobrious words grieve the spirits of those to whom they are spoken, and cut them to the heart. Slanders, like a sword, wound the reputation of those of whom they are uttered, and perhaps incurably. Whisperings and evil surmises, like a sword, divide and cut asunder the bounds of love and friendship, and separate those that have been dearest to each other. 2. There are words that are curing and healing: The tongue of the wise is health, closing up those wounds which the backbiting tongue had given, making all whole again, restoring peace, and accommodating matters in variance and persuading to reconciliation. Wisdom will find out proper remedies against the mischiefs that are made by detraction and evil-speaking.