In the seventh aliyah G-d warns that every man or beast found in the field will be smitten with a most grievous hail. Those that fear G-d bring themselves and their cattle in from the field. Moshe stretches his rod toward heaven and a fiery hail comes down to earth such as never had been seen before. Everything that is in the field, both man, beast, and every herb and tree is destroyed except in the land of Goshen where there is no hail.
Pharaoh now admits his sin and says that he recognizes the righteousness of G-d. The plague stops, but Pharaoh changes his mind again.