Mishneh Torah, Leavened and Unleavened Bread
"With a strong hand" - this [refers to] the pestilence, as it is stated (Exodus 9:3); "Behold the hand of the Lord is upon your herds that are in the field, upon the horses, upon the donkeys, upon the camels, upon the cattle and upon the flocks, [there will be] a very heavy pestilence."