'Grass' in the Bible

When the first angel blew his trumpet, hail and fire were mixed with blood and thrown on the earth. One-third of the earth was burned up, one-third of the trees was burned up, and all the green grass was burned up.

They were told not to harm the grass on the earth, any green plant, or any tree. They could harm only the people who do not have the seal of God on their foreheads.