וַיַּ֨עַשׂ יְהוָ֜ה אֶת־הַדָּבָ֤ר הַזֶּה֙ מִֽמָּחֳרָ֔ת וַיָּ֕מָת כֹּ֖ל מִקְנֵ֣ה מִצְרָ֑יִם וּמִמִּקְנֵ֥ה בְנֵֽי־יִשְׂרָאֵ֖ל לֹא־מֵ֥ת אֶחָֽד׃
이튿날에 여호와께서 이 일을 행하시니 애굽의 모든 생축은 죽었으나 이스라엘 자손의 생축은 하나도 죽지 아니한지라
Chizkuni
וימת כל מקנה מצרים, “all the domesticated livestock of Egypt died.” The Torah means to emphasize that all the livestock which died belonged to the Egyptians. The verse does not mean that all the livestock in Egypt died, as it states specifically in our verse that of the livestock owned by Israelites not a single animal died. This is why the Torah could write in verse 20 that the livestock of G-d fearing Egyptians who had brought their beasts into shelter did not die.
Or HaChaim
.כל מקנה מצרים, all the cattle of Egypt. This refers to the cattle the Egyptians had not brought indoors, this is why the words "in the field" are missing here.
Malbim
Adonoy will do this thing. The Torah explains that Hashem alone brought these two plagues (wild animals and pestilence), and not through the agency of Moshe and Aharon. Since these plagues came to enlighten them about Divine Providence, Hashem clarified that He has no need for intermediaries, for He Himself watches over the world and accomplishes everything.