At the climax of Egypt's collapse, Pharaoh completely surrenders. He not only agrees to every demand made by Moses and Aaron but ultimately begs for their prayers on his behalf. He permits the Israelites to take all their flocks and herds without any limitations. Recognizing that their departure is permanent, he understands they will need both types of animals: flocks to provide wool and milk, and herds to work the land [העמק דבר]. By allowing them to leave exactly as they had requested, Pharaoh entirely abandons his own will and previous conditions, bowing completely to the desires of the Israelites [קאסוטו]. Furthermore, he actually fulfills an earlier demand made by Moses, providing them with animals and gifts from his own wealth and that of his ministers so they can offer sacrifices to God [רש"י, חזקוני, רלב"ג].
His command for them to leave is a decisive expulsion. Some of the Israelites were afraid to venture into the unknown desert, hoping that the Egyptians might now treat them well. However, the terrified Pharaoh drove them out by force, leaving them no choice but to depart [חומש קה"ת].
The ultimate peak of his surrender is his plea for a blessing. The primary approach among commentators is that he asks to be included and mentioned in their prayers when the Israelites worship God and offer their sacrifices. There are several views regarding what this blessing entailed. Because Pharaoh himself was a firstborn, he may have been begging for his own life, asking them to pray that he would not die in the plague [רש"י, שפתי חכמים]. Others explain he simply wanted the disaster to stop so he would not suffer any further punishment because of them [הטור הארוך, משכיל לדוד]. Conversely, some suggest he was not merely looking to avoid harm, but was asking for a genuine, positive blessing for himself and his kingdom [אור החיים, רמב"ן]. A completely different approach suggests that his words are not a request for prayer at all, but rather a declaration. He is stating that just as the Israelites are blessed by their release from slavery, he too is greatly blessed by being freed from the plagues and suffering they brought upon him [הכתב והקבלה].
Driven by terror, Pharaoh finally recognizes the greatness of the Israelites and their closeness to God, realizing that true blessing can only come from those who are loved by and attached to the Creator [ביאור יש"ר]. Whether Moses actually prayed for him remains a matter of debate. Some believe Moses did not, as God already planned to punish Pharaoh at the Red Sea. Others argue that Moses would never deceive him and did indeed pray on his behalf, but Pharaoh forfeited the blessing the moment he changed his mind and pursued the Israelites [העמק דבר].
This plea brings a fascinating historical cycle to a close. The very first encounter between a Hebrew leader and a king of Egypt began with a blessing, when Jacob blessed the Pharaoh of his time. Now, the final encounter also ends with a blessing, subtly pointing back to the divine promise made to Abraham that all the families of the earth would be blessed through him [קאסוטו].