The sixth plague marks a dramatic turning point in the psychological battle between God and the king of Egypt. After a series of devastating strikes, the king's natural resilience finally breaks, and the source of his stubbornness fundamentally shifts. The primary approach among commentators highlights a clear contrast between this moment and the earlier plagues. Initially, the king hardened his own resolve, bolstered by his magicians who stood by his side to boast of their own wisdom. Now, afflicted by the boils themselves, the magicians are too ashamed to even appear in the palace, leaving the king entirely without supporters.
Beyond his isolation, the physical suffering caused by the boils was so intense that the king could not naturally withstand it. Left to his own devices, his endurance would have completely failed, and he would have been forced to release the Israelites purely out of fear and bodily agony [ספורנו, ביאור יש"ר, ביאור שטיינזלץ]. However, because such a surrender would have stemmed from intense pressure rather than true repentance, God miraculously intervened. He infused the king with supernatural strength, fortifying his spirit so he could endure the unbearable pain without breaking. This divine empowerment was designed to allow the plagues to continue, further displaying God's power to the world [ביאור יש"ר, נחל קדומים].
This shift from self-inflicted stubbornness to divine intervention also serves as a direct consequence of the king's earlier choices. Because he repeatedly chose to sin and refused to repent during the initial plagues, his fate was sealed, and the hardening of his resolve is now administered as a punishment from God [רמב"ן, מלבי"ם]. Interestingly, while this stubbornness is now divinely imposed, it ultimately reflects the king's own original and deep-seated desires [קונטרס חיבה יתירה].
Empowered by this newfound resolve, the king completely ignored the warnings of Moses and Aaron and refused to ease the crushing labor imposed on the Israelites [העמק דבר]. Noticeably, unlike in several previous plagues, he did not even ask Moses to pray for the affliction to be removed. This lack of a plea for help was likely due to God's direct intervention in strengthening his heart [אבן עזרא]. Other perspectives suggest that he did not ask for prayer because the plague was brief [הטור הארוך], or simply because the king assumed the boils were ordinary blisters, much like natural burns, which would heal on their own without the need for special prayers or medicine [בכור שור, חזקוני].
Ultimately, these events signify the realization of God's early promise to Moses [קאסוטו]. While in the earlier plagues God merely orchestrated the circumstances that allowed the king to harden his own heart, this moment represents the fulfillment of God's explicit word through direct and undeniable divine intervention [העמק דבר, רלב"ג].