What is the meaning of "Upelah"?
Rashi: His Nefesh is always angry and desirous; it seeks to swallow, and it is not satiated. Upelah is an expression of audacity, like "va'Ya'apilu" (Bamidbar 14:44), "Ofel va'Vachan" (Yeshayah 32:14).
Radak: It is haughtiness and intentional [sin]. t/he same applies to "va'Ya'apilu La'alos El Rosh ha'Har."
Radak citing his brother R. Moshe: This is like "Ofel va'Vachan", a tall fortress. One whose Nefesh is not straight, he puts himself in a fortress to take refuge from the enemy. He does not repent to Hashem and request salvation from Him.
Malbim: He calculates Ketzim (deadlines for redemption) and 'forces' the Ketz (tries to bring redemption prematurely). Many will stumble to ascend with strength and force to bring the Ketz ? "u'Vnei Paritzei Amecha Yinase'u Leha'amid Chazon v'Nichshalu" (Daniel 11:14). They will stand up false Nevi'im and cause many evils to Yisrael. Many will calculate Ketzim, and when they do not come, they leave the creed.
In what sense is his Nefesh not straight?
Rashi: His Ru'ach is not cold (calm) on him, to say 'what I already acquired is enough.' Therefore, punishments come upon him.
Radak (3): He lacks Emunah in Hashem. He is haughty, and does not fear lest evil come. So Nebuchadnetzar and his grandson Belshatzar were haughty against Hashem.
What do we learn from "v'Tzadik be'Emunaso Yichyeh"?
Rashi citing Seder Olam 28: Yechanyah ha'Melech, in the future, this one (Nebuchadnetzar) will exile him ? his virtue will stand for him. When this one will be cast from his grave 1 , Evil Merudach will raise Yechanyah, and put his chair above that of kings (Melachim II, 25:27).
Radak citing his brother R. Moshe: A Tzadik does not need to seek refuge in a fortress ? he lives in his Emunah!
Radak (3): A Tzadik, his Nefesh is lowly. He always fears Hashem. Therefore, he lives in his Emunah on Hashem, and is saved from evil that comes to the Rasha. These are Yisrael who were exiled to Bavel with Tzidkiyah. They were humbled in Galus, and did not serve idolatry. They believed in Hashem. When Koresh conquered Bavel and killed the Kasdim, Yisrael believed in Hashem and were saved; they left Galus Bavel.
Orchos Tzadikim (Sha'ar ha'Simchah DH Lachen Kol): The entire Torah is contained in Emunah.
Malbim: He does not calculate Ketzim. He lives with Emunah and believes that there is a day for Hashem ? he is quiet to Hashem and hopes for Him.
Refer to Yeshayah 14:19:2:1.
