Before Hashem begins the affliction of the Eser Makkot, the Ten Plagues, upon Egypt, Hashem informs Moshe that Hashem will "harden Paro's heart." Hashem tells Moshe that Paro will refuse to release Bnei Yisrael despite the horrific plagues placed upon his land and his people.
וַאֲנִי אַקְשֶׁה, אֶת-לֵב פַּרְעֹה; וְהִרְבֵּיתִי אֶת-אֹתֹתַי וְאֶת-מוֹפְתַי, בְּאֶרֶץ מִצְרָיִם.
And I will harden Pharaoh's heart, and multiply My signs and My wonders in the land of Egypt.
Chazal raise the question of how we reconcile this pasuk with the doctrine of b'chira chofshit - human free will. In Shmot Rabbah (13:4), Chazal quote the Amora, Reish Lakish, who quotes this pasuk in Vaera alongside a verse from Sefer Mishlei. In Perek 3, pasuk 34, we read:
When it comes to the scoffers, He will scoff...
Reish Lakish understands this idea of leitzanut - scoffing or cynicism, to mean that Hashem warns a person once, twice and then three times. If this person does not change his or her course, Hashem shuts this person's heart from Teshuva, from repentance. If a person is a scoffer, if he or she repeatedly resists change and is pursuing evil and cruelty, Hashem will make sure that this individual continues on this path. Even though a person is normally granted free will, there are situations where God will not allow this person to repent. It is when one has this deep and rigid quality of leitzanut which gets in the way of his recognition of the truth and inhibits that in others as well.
Reish Lakish explains that this quality of leitzanut was at the core of Paro's persistence in his sinfulness. This is the reason, says Chazal, that Paro was punished in such a devastating manner with the plagues. These plagues were orchestrated in such a way where the appreciation of God's supreme power was unavoidable. If one chose to resist by digging in their heels and refusing to recognize Hashem's hand in these events, then it is clear that he or she embarked on a path that one cannot remove themselves from. Reish Lakish attempts to connect this idea of a scoffer alongside the 10 plagues to emphasize Paro's desire and choice to scoff and ignore the truth of God's existence and power. With each passing plague, Paro convinced himself that Egypt and the Egyptians would be able to withstand such strength, force and power. Paro insisted on denying these truths and attempted to dishonestly claim that whatever is being experienced is surmountable.
Reish Lakish suggests that given Paro's insolence and inability to shift focus in acknowledgement of the truth and valuing what was honest, HaKadosh Baruch Hu's gave Paro his autonomy to continue on his course. Paro's heart was hardened because he led himself to the unyielding and rigid mindset of dishonesty. As Chazal note, nothing is more contrary to Hashem than falsehood.
In our own lives, we must make every effort to embrace the truth, We must confront it, and work through it even when difficult. In doing so we strengthen our bond to Hashem and all that is productive.