What is the meaning of "Hafoch Resha'im v'Einam"?
Rashi: This is like Lahfoch - in a moment they are overturned and eradicated, like Sedom.
R. Yonah: This is based on the previous two verses. One should believe that Resha'im's end is destruction; their Nefesh will be utterly destroyed, for they anger Hashem with their bodies and Sechel - "Tachbulos Resha'im Mirmah; Divrei Resha'im Erav Dam."
Malbim: Even though it looks like Resha'im are rooted strongly, when the time of their punishment comes, when their measure [of liability] is full, Hashem overturns them from one extreme to the other - in quality, quantity and situation. When one flips a tree's root above and the branches below, or a person's head below and his feet above, this is reversed - "Hafach mi'Shoresh Harim" (Iyov 28:9). Then he does not exist - "Ra'isi Rasha Aritz u'Mis'areh k'Ezrach Ra'anan; va'Ya'vor v'Hine Einenu" (Tehilim 37:35-6). This is Midah k'Neged Midah, for the Rasha goes reversed. Man is like an inverted tree; it source (his head) is above, and its branches cling to the ground. The Rasha, his head, brain and thoughts are below in the ground - he is reversed! His punishment is that Hashem reverses him - total destruction.
What is "Ya'amod"?
Rashi: It will last (R. Yonah - in their merit).
Why does it say "u'Veis Tzadikim Ya'amod"?
Malbim: Even if a Tzadik is punished, this is immediately when he sins - "Sheva Yipol Tzadik v'Kam" (24:16). His root is not uprooted, just Hashem strikes him monetarily and with [bodily] afflictions. Not only the Tzadik endures, rather, even his household - "ka'Avur Sufah v'Ein Rasha v'Tzadik Yesod Olam" (10:25). There discusses natural afflictions, and here, punishments of Hashgachah. Bereishis Rabah expounds both verses regarding Dor ha'Mabul and Noach.
