Приповісті 10:11

Another proverb, similar to the half of Pro 10:6 : A fountain of life is the mouth of the righteous; But the mouth of the godless hideth violence. If we understand 11b wholly as 6b: os improborum obteget violentia, then the meaning of 11a would be, that that which the righteous speaks tends to his own welfare (Fl.). But since the words spoken are the means of communication and of intercourse, one has to think of the water as welling up in one, and flowing forth to another; and the meaning of 11b has to accommodate itself to the preceding half proverb, whereby it cannot be mistaken that חמס (violence), which was 6b subj., bears here, by the contrast, the stamp of the obj.; for the possibility of manifold windings and turnings is a characteristic of the Mashal. In the Psalms and Prophets it is God who is called מקור חיּים, Psa 36:10; Jer 2:13; Jer 17:13; the proverbial poetry plants the figure on ethical ground, and understands by it a living power, from which wholesome effects accrue to its possessor, Pro 14:27, and go forth from him to others, Pro 13:14. Thus the mouth of the righteous is here called a fountain of life, because that which he speaks, and as he speaks it, is morally strengthening, intellectually elevating, and inwardly quickening in its effect on the hearers; while, on the contrary, the mouth of the godless covereth wrong (violentiam), i.e., conceals with deceitful words the intention, directed not to that which is best, but to the disadvantage and ruin of his neighbours; so that words which in the one case bring to light a ground of life and of love, and make it effectual, in the other case serve for a covering to an immoral, malevolent background.

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.

10:11 As a fountain provides water that sustains life, the words of the godly give life to those who hear them. In contrast, the violent intentions concealed in the words of the wicked bring death (see also 10:6; Jas 3:1-12).