He that hateth dissembleth with his lips. This and the next verse form a tetrastich. St. Jerome, Labiis suis intelligitur inimicus. But the verb here used, נכר, bears the meaning "to make one's self unknown," as well as "to make one's self known," and hence "to make one's self unrecognizable" by dress or change of countenance (1 Kings 14:5).
This is much more appropriate in the present connection than the other explanation. The man cloaks his hatred with honeyed words. And layeth up deceit within him; meditating all the time treachery in his heart (Jeremiah 9:8).
Septuagint, "An enemy weeping promises all things with his lips, but in his heart he contriveth deceits." The tears in this case are hypocritical signs of sorrow, intended to deceive the dupe.