God's absolute sovereignty over the most powerful forces of nature serves as an eternal promise of His ability to save His people. The mastery over a raging sea acts as a profound symbol of God's power to subdue any threatening force, whether it comes from physical enemies or internal spiritual struggles.
The exact nature of God's interaction with the sea is understood in several ways. One approach explains that God physically splits and tears the waters apart [מצודת ציון, שד״ל, צאינה וראינה], recalling the historical miracle of the splitting of the Red Sea [רד״ק, שד״ל]. In this scenario, the waves roar loudly as they attempt to crash back into their natural place, only to be held back by God's command [רד״ק, שד״ל]. Another perspective suggests that God demonstrates His might through contrasts, sometimes holding the waters back against their nature, and other times commanding the waves to crash and roar with great force [מצודת דוד, ביאור שטיינזלץ].
Conversely, other commentators understand the action as bringing rest and calm [מלבי״ם, אבן עזרא], or even issuing a stern rebuke to the waters [רד״ק, אבן עזרא בשם תרגום יונתן]. From this viewpoint, God's power is most evident when He silences and calms the sea precisely at the moment its waves are at their most violent and stormy [מלבי״ם, אבן עזרא]. A different interpretation suggests that God creates the very motion and ripples upon the water's surface [רש״י].
Beyond the physical imagery, the primary approach among commentators views the control of the sea as a powerful metaphor offering comfort and security. If God can master a violent ocean storm and quiet its waves, He can certainly silence the rage and chaos of the nations that oppress Israel, ultimately leading His people out of exile.
On a more personal level, the stormy sea represents the internal struggles of the human mind. The roaring waters symbolize the evil inclination, which violently threatens to drown a person in sin, often deceiving them by presenting wrongdoings as good deeds. The only way to calm this internal storm and drive away the evil inclination is by fully recognizing God's ultimate authority [אהבת יהונתן].
This absolute authority is captured by His identity as the Lord of Hosts, a title emphasizing that He is the supreme Master and Ruler over all forces, both in the heavens and on earth, holding complete and total control over all existence [מצודת דוד, רד״ק].