Sforno on Exodus 10:16/ספורנו על שמות י׳:ט״ז

1על ארץ מצרים בארבה, before the locust could destroy also the roots of the wheat and spelt and other plants they had been devouring. 10,20-23. נטה ידך על השמים, “in the direction of the atmosphere referred to as “heaven.” We have explained this in connection with Genesis 1,7.