Exodus 9:10

באדם ובבהמה UPON MAN AND UPON CATTLE — If you ask, “Whence did they obtain these cattle”? Has it not already been stated, (v. 6) “And all the cattle of Egypt died”? I reply that this judgment was decreed only against the cattle that were in the fields, as it is said, (v. 3) “[The hand of the Lord is] upon thy cattle which is in the field”, and everyone who feared the Lord took his cattle in-doors. So it is taught in the Mechilta in the comment on (Exodus 14:7) “And he took six hundred chosen chariots.”

וַיִּקְח֞וּ אֶת־פִּ֣יחַ הַכִּבְשָׁ֗ן וַיַּֽעַמְדוּ֙ לִפְנֵ֣י פַרְעֹ֔ה וַיִּזְרֹ֥ק אֹת֛וֹ מֹשֶׁ֖ה הַשָּׁמָ֑יְמָה וַיְהִ֗י שְׁחִין֙ אֲבַעְבֻּעֹ֔ת פֹּרֵ֕חַ בָּאָדָ֖ם וּבַבְּהֵמָֽה׃

And they took soot of the furnace, and stood before Par῾o; and Moshe sprinkled it up heavenwards; and it became a pox breaking out in blisters on man and beast.