Exodus 9:22
And the Lord said unto Moses, Stretch forth thine hand toward heaven, that there may be hail in all the land of Egypt, upon man, and upon beast, and upon every herb of the field, throughout the land of Egypt.
Cross-references
Exodus 9:18 predicts the worst hailstorm; this verse initiates it, fulfilling the warning within the same narrative.
In Exodus 8:5, a similar command to stretch out the hand over water initiates the plague of frogs, repeating the pattern of plague initiation.
Exodus 8:16 also has a command to stretch out the staff to bring gnats, mirroring the action here for the hail plague.
Exodus 10:21 commands stretching out the hand toward the sky for darkness, another plague initiation command.
Revelation 16:21 describes a plague of huge hailstones falling from heaven, directly echoing the Egyptian hail plague.
Joshua 10:11 recounts God hurling large hailstones on Israel's enemies, a similar use of hail as divine judgment.
Ezekiel 38:22 prophesies hailstones as judgment on Gog, paralleling the hail plague on Egypt.