I know that ye will not yet fear the Lord. True fear of God is shown by obedience to his commands. Pharaoh and his servants had the sort of fear which devils have—" they believed and trembled." But they had not yet that real reverential fear which is joined with love, and has, as its fruit, obedience. So the event showed. (See Exodus 9:34, Exodus 9:35.)
These verses seem out of place, containing, as they do, an account of the damage done by the hail, and being thus exegetical of Exodus 9:25. They are a sort of afterthought, inserted parenthetically, and prepare the way for the understanding of the next plague; since, if the damage done by the hail had extended to all the crops, there would have been nothing left for the locusts to devour.