Exodus 10:17

Now therefore forgive, I pray thee, my sin, only this once ,.... Pretending that he would never offend any more, and if he did, he did not desire it should be forgiven him, but that due punishment should be inflicted on him. These words are directed to Moses, he being the principal person that came to him with a commission from the Lord, and who was made a god to Pharaoh; and therefore he does not ask forgiveness of the Lord, but of Moses:

and entreat the Lord your God, that he may take away from me this death only ; this deadly plague of the locusts, which devouring all the fruits of the earth, must in course produce a famine, and that the death of men. Moreover, the author of the book of Wisdom says, that the bites of the locusts killed men,"For them the bitings of grasshoppers and flies killed, neither was there found any remedy for their life: for they were worthy to be punished by such.' ( Wisdom of Solomon 16:9 )Pharaoh was sensible that this plague came from God, and that he only could remove it; and therefore begs the prayers of Moses and Aaron to him for the removal of it, and suggests that he would never desire such another favour; but that if he offended again, and another plague was inflicted on him, he could not desire it to be taken away; by which he would be understood, that he determined to offend no more, or give them any occasion for any other judgment to come upon him, was he once clear of this.