What is the meaning of "Lev Tzadik Yehegeh La'anos"?
Rashi: He thinks what to answer before he answers anything.
R. Yonah: The entire day, he thinks to be humbled. One must arrange the heart to constantly suggest ideas to reach humility, love lowliness and Lehasig 1 desire for honor, "Ki Yetzer Lev ha'Adam Ra" (Bereishis 8:21) clings to it. This stumbling block made [almost] everyone stumble. The remnant [who did not stumble] are those who come close to Hashem.
Malbim: A law of Tzedek is not to talk until weighing the matter with his Sechel. Not only what he says - also what he answers, a Tzadik's heart thinks what to answer, and whether or not to answer. Know what to answer a heretic (Avos 2:14), "Al Ta'an Kesil k'Ivalto" (below, 26:4). It is a Mitzvah not to say something that will not be heeded (Yevamos 65b).
Surely this is a printing mistake. Perhaps the text should say 'Lahaflig' or 'Lisno' (to go far from desire for honor, or to hate it. - PF)
How do Resha'im's mouths express evil?
R. Yonah: It is not enough for them that their hearts are not humbled, and they do not strive to acquire lowliness. Their mouths constantly express evil, to make people fear them. Some do many acts in order that people will honor them. Their evil does not reach that of those who rule via force. Those who put fear on people are judged in Gehinom for all generations (Rosh Hashanah 17a).
Malbim: Resha'im, the spring (source) of their words is not in the heart. Rather, their mouths express evils. Evil talk - Leshon ha'Ra, Rechilus and heresy - their source is in the mouth, and not in the heart.
