Brachos 55a: A good king needs mercy. Just like a river branches into two, Hashem can veer a king's heart for good or bad, according to the merits of his subjects). Malbim - even though an individual's heart is in his Reshus and he has choice, the king is different. Since happiness of the Klal depends on his choice, if he will choose evil, he will ruin many. Therefore, his heart is in Hashem's hand. For matters of the Klal, he has no choice. This is compared to streams of water. When they descend from mountains and many sources, they gather to be a gushing river. From the river it divides to many channels. The Klal depend on these streams. If they will not supervise to divert them to the places that need them, they will pass from settled places to Midbaros and forests, or they will flood fields in plains, or destroy cities in valleys. Therefore, people dig channels to divert the water to the places that need it, and divert it from places that do not need it, and all the more so from place where it can damage and flood. So the king's heart - his deeds can afflict the Klal or help it, make war or Shalom. If the Klal merits, Hashem veers the king's heart for good, and conversely. Hashem does not wait to change the final deed like His desire. Rather, from the beginning the king's heart leans towards Hashem's desire, just like streams are tilted [in the desired directions] where they first separate.

R. Yonah: Many depend on the king. Because Hashem gave to him power to kill and keep alive, to harm and benefit, He guards his heart from leaning to evil, [rather,] to do Hashem's decree. Therefore, hearts' ambitions should be to fear Hashem, and not to fear the king's anger. One should request mercy from Hashem and put his eyes (hope) to Him, for He veers the king's heart as He desires, just like a man diverts streams of water to wherever he wants.

R. Yonah (3:26): Striking and salvation is not in the hand of the one who hits him. An aspect of Bitachon is not to trust in man to benefit or save him, only if Hashem will decree. "Arur ha'Gever Asher Yivtach ba'Adam" (Yirmeyah 17:5), "Chidlu Lachem Min ha'Adam" (Yeshayah 2:22). He truly knows that man could not harm him - "bEi'lokim Batachti Lo Ira Mah Ya'aseh Vasar Li", "Hashem Li Lo Ira Mah Ya'aseh Li Adam" (Tehilim 56:5, 118:6). When the affliction comes, he turns his heart to Hashem - "Hine k'Einei Avadim El Yad Adoneihem" (ibid. 123:2). He does not fear the one who strikes him. He increases fear of Hashem, and hopes to Him. His heart does not become soft, and he does not fear the person ¹ . Closeness of the Tzarah and lack of an idea for salvation does not confound him, for Hashem can save - "v'Lo Misken Allies" (Shmuel I, 2:3), "v'Harei Imo Feuds" (Tehilim 130:7). The stronger the hope is in Hashem, the greater is the level of the Nefesh.