What is the significance of "Zecher Tzadik li'Vrachah" here?
Rashi: One who mentions a Tzadik, he blesses him. (Verse 6 discussed Brachos on a Tzadik's head.)
R. Yonah #1: Verse 6 discussed Brachos from Shamayim; here is a Brachah from people.
R. Yonah (6): Verse 6 discussed Brachos that are carried out; this is a Brachah in remembrance and speech.
R. Yonah #2: People will mention it only for a Brachah, but not for detriment or without need.
Malbim: Zecher is mentioning him via his deeds.
How will Resha'im's names rot?
Yuma 38b: People will not be called on their names 1 .
Rashi: No one wants to mention his name; it is forgotten automatically.
R. Yonah: Just like rotting wood, it itself causes the corrosion, so the Rasha causes detriment said about him. It is not because the teller loves to tell detriment.
Orchos Tzadikim (Sha'ar ha'Chanifus DH v'Od Yesh): One should not tell or mention the good of Resha'im. If one does not want to tell his evil, do not tell his good!
Malbim: The Rasha, not only are his deeds forgotten - also his name and essence rot automatically, for Resha'im leave no remnant of the Nefesh or the species 2 .
Shoshanim l'David (Yuma 3:11): Why was a Navi named Michah? Ba'al Pesel Michah preceded him, and we do not find that he repented! The Rasha's real name was not Michah, rather, Sheva ben Bichri (Sanhedrin 101b). (The names Menasheh and Elisha persisted, for Tzadikim were called so before the Resha'im; also, the Resha'im repented. The Gemara asked about a boy named Do'eg, and answered that due to this, his end was calamity. How can we answer for Shamu'a (Nechemyah 11:17, 12:18; R. Eliezer ben Shamu'a), Elisha ben Shafat, and Palti ben Layish? These were names of evil Meraglim (Bamidbar 13:4, 5, 9))! Perhaps the verse means that they will not be used often. - PF)
This implies that their descendants will die out. We find that seed of Resha'im persisted, e.g. Amalek, Bnei Eli, evil kings of Beis David
Why does it say Tzadik (singular) and Resha'im (plural)?
Yuma 38b: The Tzadik will be blessed by himself; when cursing a Rasha, all Resha'im are cursed with him.
