1)
What is the meaning of "Pen Yechasedcha Shome'a"?
1.
Rashi: The one who hears will disgrace you, and call you a slanderer. The Targum of "Cherpas Egypt" (Yehoshua 5:9) is Chisudei Mitzra'ei.
2.
Malbim: Aside from shame via your opponent in the quarrel, everyone who hears will shame you more. They will say that you speak Leshon ha'Ra, go tale-bearing and reveal secrets.
2)
What do we learn from "v'Dibasecha Lo Sashuv"?
1.
Malbim: Afterwards, when you want to retract your Leshon ha'Ra, you cannot. You will attain constant shame and disgrace.
