1)
What is the meaning of "Yafi'ach"?
1.
Rashi: It is an expression of speech, for all speech is via breath of the mouth.
2)
Why does it say "Yafi'ach Kezavim Ed Shaker"?
1.
Orchos Tzadikim (Sha'ar ha'Sheker DH ha'Revi'i): This Midah can bring him to testify falsely, because he loves Sheker.
2.
Malbim: He speaks falsely and testifies Sheker in matters of Emunah.
