The Belzer Rav zt'l was traveling from Tel Aviv to Kfar Chabad to bake matzos for Pesach. It was Erev Pesach, and the gaba'im who were taking him were rushing because it was late. They had to bake matzos and get back in time for yom tov. Suddenly, the Belzer Rav told them to stop the car. He got out and stood on the side of the road for a moment, where he was heard saying הושענא מבהלה נפש, "Save the soul from confusion". He felt himself being swept up in the panic of others, so he stopped the car, despite the late hour, and he davened that he should have a calm mind, without worry and panic.
It states (Tehillim 34:1) לִפ ְנֵי טַע ְמוֹ אֶת ׁ ַנּוֹתוֹבְּש לְד ָוִד וַיֵּלַ ךְ ׁ ֵ הוּוַיְגָרֲש אֲבִימֶלֶ ךְ. The pasuk is saying ׁ ֵ הוּוַיְגָרֲש, that Avimelech banished Dovid, and וַיֵּלַ ךְ Dovid walked. These two expressions, ׁ ֵ הוּוַיְגָרֲש וַיֵּלַ ךְ, banished and walking, seem contradictory. Generally, when one is banished, he runs. It isn't וַיֵּלַ ךְ, walking away. But the pasuk is telling us the calmness that Dovid HaMelech always possessed. Even when he was banished, he believed that it was from Hashem, and therefore, he was calm and tranquil. He didn't lose his peace of mind.
The Rambam (Hilchos Malachim 7:15) writes, "When a person is at war, he must trust in Hashem Who saves Yisrael at a time of tzarah. Whoever thinks about the war and becomes afraid, he is transgressing a lav, as it states (Devarim 20:3) תַּחְפ ְּ זוּ וְאַל ת ִּ ירְ אוּ אַל לְב ַבְכֶם יֵרַ ךְ אַל מִפ ְּנֵיהֶם תַּע ַרְ צוּ וְאַל, 'Let your hearts not be faint; you shall not be afraid, and you shall not be alarmed, and you shall not be terrified because of them.'"
Rabbeinu Yonah (Shaarei Teshuvah 3:32) explains the pasuk (Devarim 20:1) לַמ ִּלְחָמָה תֵצֵא כִּי מֵהֶם תִירָא לֹא ָמִמְּך רַב עַם וָרֶכֶב סוּס וְרָא ִיתָ ָאֹיְבֶך עַל, "When you go out to war against your enemies, and you see horse and chariot, a people more numerous than you, you shall not be afraid of them." He writes, "The Torah is warning us that when a person sees a tzarah approaching, Hashem's salvation should be in his heart, and he should rely on it. As it states (Tehillim 85:10) יִשְׁעוֹ לִירֵא ָיו קָרוֹב אַ ךְ, ' Truly, His salvation is near those who fear Him.' Also, it states (Yeshayahu 51:12) מֵא ֱנוֹשׁ וַת ִּירְאִי ְּאַת מִי יָמוּת, 'who are you that you fear man who will die.'" So, it is a Torah obligation not to be afraid. ָמִמְּך רַב עַם וָרֶכֶב סוּס וְרָא ִיתָ, we see "horse and chariot, a people more numerous than you" and yet we mustn't be afraid. As Rabbeinu Yonah writes, ויבטח בלבבו 'ה ישועת תהיה עליה, "Hashem's salvation should be in his heart, and he should rely on it."
It states (Tehillim 91:9) מחסי 'ה אתה כי. A popular translation of this pasuk is "You, Hashem, are my refuge." According to this translation, אתה, "You" is addressing Hashem. "You, Hashem, are my refuge." Rashi however writes, 'ה אמרתה – אתה כי מחסי. Rashi is adding to the translation of the pasuk the word אמרת. The pasuk is speaking to the Yid, and it states that אמרתה אתה, you say, מחסי 'ה, Hashem is my refuge. You say this, you trust in Hashem, and that is your salvation.
Then Rashi writes, קצר מקרא זה והרי, that this is a shortened pasuk. Literally, this means that the pasuk is written in brief, because it left out the word אמרת. We can also explain that Rashi is hinting to us that with this מקרא קצר, short pasuk, a short phrase of expressing bitachon – all that he says is מחסי 'ה, "Hashem is my refuge" – and that is sufficient for him to receive his salvation.
The chapter describes many dangers. For example, it states in this chapter (91:5) תירא לא יומם יעוף מחץ לילה מפחד, "You will not fear the fright of night, the arrow that flies by day." This is all because you say מחסי 'ה, "Hashem is my refuge."
Regarding kriyas Yam Suf, it states (Shemos 14:20) וּמִש ְּׂמֹאלָם מִימִינָם חֹמָה לָהֶם וְהַמ ַּיִם, "The water was to them like a wall from their right and from their left." The Imrei Baruch of Vizhnitz zt'l says that וְהַמ ַּיִם (with the kollel) is gematria 102, which is the gematria of אמונה. And להם is gematria 75, בטחון. So, חֹמָה לָהֶם וְהַמ ַּיִם means that emunah and bitachon is the wall that protects us. No missile can penetrate this strong wall.
