דֶּבֶר Dever, pestilence is the fifth plague in which God killed all types of domestic animals such as horses, donkeys, camels, cattle (cows), and herds (sheep). They died one after another so they were considered five plagues. For this plague, Scripture states, “then the hand of HaShem will strike…” (Ex. 9:3) This is difficult since regarding the other plagues it states, “finger of God,” why does it now say, “Hand of God?” But because this plague involved five species of animals it was considered like five plagues. This Is what the author of Sefer Toldot Yitzchak¹⁵⁵ writes.

footnotes: ¹⁵⁵ Commentary on the Torah written around: 1475 - c.1535 A commentary explaining the simple and midrashic meaning of the text, most of the book's content can already be found in earlier works. (Sefaria)