Why didn't Pharaoh want to get rid of the frogs right away?

[TonyChanYT]

Exodus 8:

6 So Aaron stretched out his hand over the waters of Egypt, and the frogs came up and covered the land. 7But the magicians did the same things by their secret arts; they also made frogs come up on the land of Egypt.
8Pharaoh summoned Moses and Aaron and said, “Pray to the Lord to take the frogs away from me and my people, and I will let your people go to offer sacrifices to the Lord.”
9Moses said to Pharaoh, “I leave to you the honor of setting the time for me to pray for you and your officials and your people that you and your houses may be rid of the frogs, except for those that remain in the Nile.”
10 “Tomorrow,” Pharaoh said.

Why didn't Pharaoh want to get rid of the frogs right away? Why wait until tomorrow? Why suffered the night of frogs running around all over the place?

Pharaoh seemed to be deliberate and purposeful in his answer "Tomorrow". What was he thinking?

Gill explained:

And he said, tomorrow,.... Which according to Bishop Usher was the twenty sixth day of Adar, or February. It may seem strange that Pharaoh, and his people, being so greatly distressed with this plague, should not desire that the Lord would be entreated to do it immediately, and not put it off to another day: two reasons are usually given;
one is, he might hope that it would by that time go off of itself, and then he should not be beholden to the Lord, nor to Moses;
and the other is, that he thought an affair of this kind could not be done immediately, but that it required time for making the intercession, and performing rites and ceremonies, which he supposed might be used, as were by his magicians; and it might be now the evening of the day, and therefore deferred it till tomorrow:

Whatever Pharoah was thinking, I sense pride in his answer.

 

[Stumpmaster]

Pharaoh seemed to be deliberate and purposeful in his answer "Tomorrow". What was he thinking?