The mouth of the righteous is a fountain of life, but the mouth of the wicked conceals violence.
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.
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...
a well--or, "source" of good to himself and others (Joh 7:37-38). On last clause, see on Pro 10:6.