In prophecy, hailstones represent God’s discipline of false prophets. The hailstones are used to destroy their deceptive teachings.

And the LORD will cause his majestic voice to be heard and the descending blow of his arm to be seen, in furious anger and a flame of devouring fire, with a cloudburst and tempest and hailstones.  Isaiah 30:30

In a rant against the false prophets, the Lord had compared them to whitewashed walls. The Lord says he will rain down hail on them until the whitewash is beaten off!

Therefore thus says the Lord GOD: I will make a stormy wind break out in my wrath; and there shall be a deluge of rain in my anger, and great hailstones in wrath to destroy it. Ezekiel 13:13

The walls are symbolic, as is the hail that destroys them. The false prophets were exposed, as their predictions that God would intervene and stop Babylon, proved false. Interestingly, the walls of Jerusalem were destroyed.

Hailstones are also listed among the torments that await Gog and their allies.

With pestilence and bloodshed I will enter into judgment with him; and I will rain upon him and his hordes and the many peoples that are with him, torrential rains and hailstones, fire and brimstone. Ezekiel 38:22