And the Lord said unto Moses, stretch out thine hand over the
land of Egypt
First one way, and then another, towards every quarter, and every part of the land, to signify that the following plague would come upon the whole land:
for the locusts, that they may come up upon the land of Egypt;
the stretching out of his hand was to be the signal to them to come up and spread themselves over the land, which was brought about by the mighty power of God; for otherwise there was no such virtue in the hand or rod of Moses, to have produced so strange an event:
and eat every herb of the land, even all that the hail hath left;
the wheat and the rye, or rice, the grass, herbs, and plants, it had beat down, but not utterly destroyed, as well as some boughs and branches of trees which were left unbroken by it.