Seeing as all the animals had died in the plague of Dever, which animals were stricken with boils?
Rashi (citing the Mechilta): Only the animals in the field died during Makas Dever. 1 Refer to 9:3:1:1 and its note.
Gur Aryeh expands upon Rashi's approach, refer to 9:10:1.1:1.
But according to Ramban (to 9:3), Dever struck all the Egyptian's animals, even those in the houses! See 9:6:151:1* for suggested answers.
What are the implications of "Shechin Ava'bu'os, Pore'ach"?
Bava Kama 80b: It implies boils that are wet on the outside and dry on the inside. 1
See Torah Temimah, note 1. Refer also to Devarim 28:27:1.
QUESTIONS ON RASHI
Rashi writes: "From where did they have any animals? ... [Prior to the plague of Dever,] those [Egyptians] who feared Hashem, fled with their animals into their homes." But if so, why didn't Moshe warn them outright to do so -- as he later did before the Makah of Barad (9:19)? And why doesn't the Torah record their actions (as it later will by Makas Barad - 9:20)?
Gur Aryeh: Had Moshe warned them outright, 'Bring your animals in from the fields!', they all would have done so, and the plague of Dever would barely have been evident! The hail, on the other hand, was unmistakably visible, and it destroyed everything else that could not be brought indoors. 1 Therefore, before Barad, Hashem sent a warning to the Mitzrim to bring in their animals. Any Mitzri who did so was fulfilling the word of Hashem, and deserving of praise; and whoever failed to do so was flouting His word. By Dever, on the other hand, Hashem sent no explicit directive (as explained above), such that those who left their animals in the fields cannot be called 'disregarding the word of Hashem.' 2 Nonetheless, about those Egyptians who cared enough to "read into" Moshe's words, and to get their animals out of the fields (where the Dever was about to strike), Rashi may indeed say that they feared Hashem; they believed that the Makah was coming. 3
Also refer to 9:19:1:1 and 9:19:151:1.
Gur Aryeh: On the contrary, Hashem wished that the animals remain in the fields, and be stricken by the Dever!
Gur Aryeh: Rashi cites the Mechilta, that the horses Pharaoh later used to chase after the Bnei Yisrael to the Yam Suf, must have been "from those Egyptians who feared Hashem." This too refers to the latter group, who brought in their animals before Dever as well. Also see Maharal (Gevuros Hashem Ch. 33).
