1)
Why does it say "Amar va'Yavo Arov"?
1.
Radak: Hashem desired, and aroused evil Chayos to come.
2.
Malbim: Dam and Tzfarde'a were via Aharon, who struck with his staff. Hashem Himself brought Arov, without a Shali'ach.
2)
Why are lice mentioned after Arov?
1.
Malbim: The lice did not leave Pharaoh, like the verses (Shemos 8:13-15) imply. The verse teaches that when Arov came, there were still lice in all Egypt's borders; the two plagues applied at the same time.
3)
Were the lice in all of Egypt?
1.
Radak: Yes - "Kol Afar ha'Aretz Hayah Chinim" (Shemos 8:13).
