출애굽기 10:15의 주석

כל ירק means any green leaf (not “any herb”, since it speaks of the ירק of the trees); old French verdure.

ויכס את עין כל הארץ ותחשך הארץ, “it covered the surface of the entire land and the land was darkened.” There was no area which remained free from locusts. The matter is comparable to Yoel 2,9: “they rush up the wall, they dash about in the city; they climb into the houses, they enter like thieves by way of the windows.” The word עין here is derived from גוון, i.e. all the normal colors on earth turned to look black.

A green leaf. Rashi is answering the question: How can the word ירק (green vegetable) apply to trees? For it is written (Bereishis 9:3): “ כירק עשב (as the vegetable herbs),” and herbs in the fields are referred to as ירקות . Therefore Rashi explains it as “a green leaf,” as if the verse had actually said “green leaf.” Rashi proves this from “Verdure in Old French” which means green leaf [and comes from the root of verd, “green”]. And so it is in Hebrew.

ותחשך הארץ, “the earth became darkened;” from the amount of shade produced by the flying swarms of locusts.