See here, 1. How industrious a good man is, by communicating his goodness, to do good with it: His mouth, the outlet of his mind, is a well of life; it is a constant spring, whence issues good discourse for the edification of others, like streams that water the ground and make it fruitful, and for their consolation, like streams that quench the thirst of the weary traveller. It is like a well of life, that is pure and clean, not only not poisoned, but not muddled, with any corrupt communication. 2. How industrious a bad man is, by concealing his badness, to do hurt with it: The mouth of the wicked covers violence, disguises the designed mischief with professions of friendship, that it may be carried on the more securely and effectually, as Joab kissed and killed, Judas kissed and betrayed; this is his sin, to which the punishment answers (Pro 10:6): Violence covers the mouth of the wicked; what he got by violence shall by violence be taken from him, Job 5:4, Job 5:5.

The mouth of a righteous man is a well of life,.... Like a fountain of living water, continually running and flowing with water, wholesome, reviving, and refreshing; so the righteous man's mouth, out of the abundance of his heart, overflows with good things, which minister grace to the hearers, and are for the use of edifying; things that are pleasant and profitable, grateful and acceptable, comforting, refreshing, and pleasing, and which tend to the good of the life that now is, and that which is to come;

but violence covereth the mouth of the wicked; so that nothing comes out of it but what is pernicious and hurtful; what savours of rapine and violence; nothing but lying and deceit, cursing and swearing, and such like filthy and corrupt communication; See Gill on Pro 10:6. The Targum is, "the mouth of the ungodly covers injury"; which is meditated in the heart; so the Vulgate Latin version.

a well--or, "source" of good to himself and others (Joh 7:37-38). On last clause, see on Pro 10:6.