What is the meaning of "Mera Makshiv Al Sefas Aven"?
Rashi: A Rasha accepts Leshon ha'Ra and false witnesses.
R. Yonah #1: Mera is a noun, like "u'Shneihem ha'Melachim Levavam l'Mera" (Daniel 11:27). ['Ish' is omitted], like "va'Ani Tefilah" (Tehilim 109:4) - I am an Ish Tefilah,
R. Yonah #2: Mera is an adjective, like "Chanef u'Mera" (Yeshayah 9:16).
Malbim: This is Matzref la'Kesef. He hears the desires - Etz ha'Da'as Tov v'Ra. This pertains to the Safah (lip), which is more external than the tongue. One distinguishes Tov and Ra via the senses and Da'as; the lips hint to Da'as. One who hearkens to desires that are known [to be forbidden], and switches good for evil, he is Mera.
does it say "Sheker Mezin Al Lashon Havos"?
Rashi: Mezin is like Ma'azin; one who lies, he hearkens to bad things. R. Yonah - there are two groups that receive Leshon ha'Ra. One is intentional sinners (Mera). The other is liars. An intentional sinner wants to find blemishes and guilt in people. He listens when people tell these about others, and he believes them. One who desires a matter, he tilts his heart to believe it, and all the more so he leans his ear to hear it. A liar is not used to seeking Emes. He puts what he hears in his heart and accepts them without investigation. He is not concerned to direct the matters to Emes. The proper Midah is to detest hearing Leshon ha'Ra. If he hears it, he does not believe it and does not tell it. He does not refrain from loving and honoring his colleague amidst Safek [that the Leshon ha'Ra is true], until he clarifies the Emes. However, he is concerned in his heart, and guards himself from the one who was spoken about. Even though it is improper to believe Leshon ha'Ra, one should be concerned for it (Nidah 61a).
Malbim: This is Kor la'Zahav. Lashon pertains to Binah. If one ruins Binah, he brings breakage and opposition to existence; this is Sheker. He switches Emes and Sheker. A furnace for gold is needed to remove the dross and mixture of heresy in it.
