How does Ed Emes save lives?
R. Yonah: It saved the Nefesh of the oppressor and the oppressed. The oppressed gets back what was taken. He saves the oppressor from sin and blood liability, and his Nefesh from Gehinom.
Malbim: He testifies Emes in front of Beis Din, and saves one who was sentenced to die via false witnesses.
What is "Yafi'ach Kezavim"?
R. Yonah: This is like "Yafi'ach Emunah Yagid Tzedek" (12:17). One who always speaks Kezev, even if he did not testify falsely in Beis Din, he is an Ish Mirmah. It is easy for him to swindle his colleague, since he does not despise Sheker, and it is fluent on his lips. He will not separate from it when his Yetzer encounters them, unless he hates and distances Sheker.
Malbim: If the one who wants to save will say Sheker, he cannot say clear Sheker, rather, Kezavim, which seem true at the time he says them. Yafi'ach is something that is incomplete speech. He does not save Nefashos, for it is guile. He is called Matzil Nefashos only if it is via Emes.
