Rashi on Exodus 9:24/רש"י על שמות ט׳:כ״ד

1מתלקחת בתוך הברד [AND FIRE] FLASHING UP AMIDST THE HAIL — a miracle within a miracle! Fire and hail mingled, although hail is water! But in order to perform the will of their Creator they made peace one with the other (Exodus Rabbah 12:4).