וַיְהִ֣י בָרָ֔ד וְאֵ֕שׁ מִתְלַקַּ֖חַת בְּת֣וֹךְ הַבָּרָ֑ד כָּבֵ֣ד מְאֹ֔ד אֲ֠שֶׁר לֹֽא־הָיָ֤ה כָמֹ֙הוּ֙ בְּכָל־אֶ֣רֶץ מִצְרַ֔יִם מֵאָ֖ז הָיְתָ֥ה לְגֽוֹי׃
און עס איז געװען אַ האָגל, מיט אַ פֿלאַקעריקן פֿײַער אין מיטן האָגל, זײער אַ שװערער, װאָס אַזאַ װי ער איז ניט געװען אין גאַנצן לאַנד מִצרַיִם, פֿון זינט עס איז געװאָרן צום פֿאָלק.
Rashi
מתלקחת 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).
Chizkuni
ואש מתלקחת בתוך הברד, “and fire was contained within the hail stones,” it is clear that after the hail had hit the ground, that this fire started conflagrations. [Otherwise who would have known that there was fire inside the hail stones? Ed.]
Sforno
ואש מתלקחת בתוך הברד. Driven by the immense velocity and pressure of the descending hailstones. The heat generated in the atmosphere resulted in unnatural sounds being heard everywhere. Both hard and soft plants were destroyed by the hail. Verse 25 spells all this out in detail.