The next time Moses and Aaron came before Pharaoh, he appeared somewhat relenting, and asked them who was to participate in the worship the Israelites wanted to hold in the desert.
When they told him that everyone without exception, young and old, men and women, and animals, were to go, Pharaoh suggested that only the men should go, and that the women and children, as well as all their possessions should remain in Egypt.
Moses and Aaron would not accept this offer, and Pharaoh became angry and ordered them to leave his palace. Before leaving, Moses warned him of new and untold suffering. But Pharaoh remained adamant, even though his advisers counselled against further resistance.
As soon as Moses left the palace, he raised his arms toward heaven and an east wind brought swarms of locusts into Egypt, covering the sun, and devouring everything green that had escaped the hail and previous plagues.
Never in the history of mankind had there been such a devastating plague of locusts as this one.
It brought complete ruin upon Egypt, which had already been thoroughly ravaged by the previous catastrophes. Again Pharaoh sent for Moses and Aaron, and implored them to pray to G-d to stop the plague. Moses complied, and G-d sent a strong west wind that drove the locusts into the sea.
When relief came, Pharaoh's obstinacy returned to him, and
he refused to liberate the people of Israel.