John Gill's Exposition of the Whole Bible
Proverbs 14:7
Go from the presence of a foolish man,.... A wicked one; avoid him, shun his company, depart from him, have no fellowship with him, it, being dangerous, infectious, and hurtful;
when thou perceivest not [in him] the lips of knowledge; when it is observed that his lips pour out foolishness, what is corrupt and unsavoury, unchaste and filthy; what does not minister grace to the hearers, nor is for the use of edifying, nor any ways improving in useful knowledge, but all the reverse: the Targum is,
"for there is no knowledge in his lips,''
in what is expressed by them; some understand this ironically, and render the words thus, "go right against a foolish man" f; join in company with him, "and thou shalt not know the lips of knowledge", or learn anything by him; if you have a mind to be ignorant, keep company with a foolish man; so Jarchi and Gersom: or rather to this sense the words may be rendered, "go to a foolish man, seeing thou knowest not the lips of knowledge" g, since thou dost not approve of wise and knowing men, whose lips would teach knowledge; and despisest the Gospel, and Gospel ministers the pope of Rome, as Cocceius on the text serves, and hear him, what his holiness and infallibility says; or some other false teacher.
f לכ מנגד לאיש כסיל "e regione viri stulti", De Dieu; so Gussetius, p. 495. and Schultens g "Abi ut stes cora in viro stolido", Cocceius.