How is "Migdol Oz Shem Hashem"?
R. Yonah: One is saved from the affliction via mentioning His name and praying to him.
Malbim: It is the true tower of strength.
What is the meaning of "Bo Yarutz Tzadik v'Nisgav"?
Rashi: He will be strengthened.
R. Yonah #1: A Tzadik runs in His name, and trusts in Him and does not fear stumbling - "v'Im Tarutz Lo Sikashel" (4:12).
R. Yonah (according to Mashal): When a person runs, he cannot see well if there is a stumbling block on the road. One is careful not to go on a road until he, knows whether he will be safe, and if there is terror around it. A Tzadik trusts in Hashem that "Lo Se'unah Elecha Ra'ah" (Tehilim 91:10). If mishaps of the time befall him, he will be saved from them. "Nisgav" is being saved from every affliction - "u'Vote'ach ba'Shem Yesugav" (below, 29:25), "Ya'ancha Hashem b'Yom Tzarah Yesagevcha" (Tehilim 20:2). One who trusts in Hashem is called a Tzadik, for Bitachon is among the highest levels in fear. Also, one who has sins must fear [punishment for] them. It says "Yir'ei Hashem Bitchu va'Shem" (ibid. 115:11), for this is a higher level of Bitachon than for commoners [who must fear due to their sins].
R. Yonah #2: A Tzadik finds in Bitachon in Hashem strength in the Nefesh to run and not weary, i.e. to toil night and day. His heart trusts in Hashem, and knows that 'the employer is faithful to pay the worker's wage' (Avos 2:19). Therefore, the days of Avodah seem to him "like a few days" (Bereishis 29:2). Via Bitachon, he is "Nisgav" (elevated) over every affliction. "V'Koyei Hashem Yachalifu Ko'ach
