Charles H. Spurgeon on Psalms 91:3

Pestilence. It is from a word (rkd) that signifies to speak, and speak out; the pestilence is a speaking thing, it proclaims the wrath of God amongst a people. Drusius fetches it from the same root, but in piel, which is to decree; showing that the pestilence is a thing decreed in heaven, not casual. Kirker thinks it is called rkd, because it keeps order, and spares neither great nor small. The Hebrew root signifies to destroy, to cut off, and hence may the plague or pestilence have its name. The Septuagint renders it yanatos, death, for ordinarily it is death; and it is expressed by "Death, "Re 6:8, he sat on the pale horse, and killed with sword, hunger, death, and beasts of the earth; it refers to Eze 14:21, where the pestilence is mentioned. Pestilence may be from a word which signifies to spread, spoil, rush upon, for it doth so; 2Sa 24:15, seventy thousand slain in three days; and plague, a plhgh from plhssw, to smite, to wound, for it smites suddenly, and wounds mortally; hence it is in Nu 14:12, "I will smite them with the pestilence." This judgment is very grievous, it is called in Ps 91:3 the "noisome pestilence, "because it is infectious, contagious; and therefore the French read it, "de la peste dangereuse, "from the dangerous pestilence, it doth endanger those that come near it: and Musculus hath it, a peste omnium pessima, from the worst pestilence of all: and others, the woeful pestilence; it brings a multitude of woes with it to any place or person it comes unto, it is a messenger of woeful fears, sorrows, distractions, terrors, and death itself. William Greenhill.