God's decision to keep Pharaoh alive despite his ongoing rebellion is not a sign of divine limitation, nor does it imply that the Egyptian ruler is spared from deserving death. Instead, his survival is a deliberate delay. God sustains Pharaoh, holding back the severe punishment he has earned, to achieve a profound educational and historical purpose that impacts both the king himself and the rest of humanity [הכתב והקבלה, ביאור יש״ר, ביאור שטיינזלץ, קאסוטו].
The primary reason for extending Pharaoh's life is to confront him directly with divine power. The primary approach among commentators highlights a principle of measure for measure. At the very beginning of the conflict, Pharaoh arrogantly claimed that he did not know God. Therefore, God keeps him alive specifically to expose his foolishness, break his pride, and force him to acknowledge God's absolute mastery over the world through the ensuing plagues [רשב״ם, אור החיים, חזקוני, מלבי״ם, רלב״ג]. However, this display of power in Egypt represents only a fraction of God's true might, with His complete greatness reserved for the future [רבנו בחיי]. A completely different perspective suggests that this display of power actually represents God's mercy, patience, and kindness. By delaying punishment, God offers Pharaoh an opportunity to repent, reflecting the principle that He does not desire the death of the wicked [ספורנו, הכתב והקבלה].
The second purpose of sparing Pharaoh is to ensure that God's name becomes known across the entire world. The primary approach among commentators agrees that this is not a personal instruction for Pharaoh to travel the globe spreading God's glory, especially since he ultimately drowns in the sea. Rather, it means that the witnesses to these events, including the surviving Egyptians and other nations, will be the ones to share the story with future generations [אבן עזרא, העמק דבר, ביאור יש״ר]. A unique interpretation connects the spreading of this message to the bright clarity of a sapphire stone. Just as the sky clears after being covered by clouds, God's judgment against the wicked purifies the world from spiritual darkness, making divine providence clear, bright, and visible to all [הכתב והקבלה].
Ultimately, bringing justice upon someone who stubbornly defies God serves a greater universal good. It elevates God's name, makes His righteous judgment known, and teaches a lasting lesson that draws people everywhere closer to serving Him [ספורנו, בעל הטורים, אור החיים, מלבי״ם, קאסוטו].