In the first aliyah, Moshe and Aharon go again to Pharaoh at G-d's command and say to Pharaoh: "Od Masai" (until when) "will you refuse to humble yourself and let my people go?" They continue to say that if Pharaoh doesn't let them go, a plague of locusts will begin, and devour everything that yet remains from the previous plagues. They then leave, and Pharaoh's servants say to Pharaoh that he should please let them go already, they've had enough.
Moshe and Aharon are brought in again and Pharaoh said "Go, but leave your children." Moshe and Aharon then leave again.
