ה' הצדיק, “the Lord is the righteous One;” the reason why Pharaoh acknowledged this in connection with the plague of hail more than with any other plague, was that G–d had issued a warning to the people that G–d had issued a warning to the people to take refuge from the lethal effects of the hail if they did not move indoors. (verse 19) When he added: “I and my people are wicked,” this was an admission that by not bringing their livestock indoors they themselves had caused them to die. (Shmot Rabbah 12,5)

כצאתי את העיר, “as soon as I leave the capital, etc.” The reason why Moses had to pray more in order to stop the plague of hail than any of the other plagues, that the Torah had written that the G–d fearing people had taken his advice (verse 20) and had been saved. The Torah had stated that the capital was full of beasts which served the Egyptians as deities. Had Moses raised his hands in prayer in the capital this might have been misunderstood as his praying