Ezekiel 9:4
2 Next I noticed six men coming from the direction of the upper gate that faces north, each with his war club in his hand. Among them was a man dressed in linen with a writing kit at his side. They came and stood beside the bronze altar. 3 Then the glory of the God of Israel went up from the cherub where it had rested to the threshold of the temple. He called to the man dressed in linen who had the writing kit at his side. 4 The Lord said to him, “Go through the city of Jerusalem and put a mark on the foreheads of the people who moan and groan over all the abominations practiced in it.” 5 While I listened, he said to the others, “Go through the city after him and strike people down; do not let your eye pity nor spare anyone! 6 Old men, young men, young women, little children, and women—wipe them out! But do not touch anyone who has the mark. Begin at my sanctuary!” So they began with the elders who were at the front of the temple.
Revelation 9:4
1 Then the fifth angel blew his trumpet, and I saw a star that had fallen from the sky to the earth, and he was given the key to the shaft of the abyss. 2 He opened the shaft of the abyss and smoke rose out of it like smoke from a giant furnace. The sun and the air were darkened with smoke from the shaft. 3 Then out of the smoke came locusts onto the earth, and they were given power like that of the scorpions of the earth. 4 They were told not to damage the grass of the earth, or any green plant or tree, but only those people who did not have the seal of God on their forehead. 5 The locusts were not given permission to kill them, but only to torture them for five months, and their torture was like that of a scorpion when it stings a person.
Notes and References
"... The thought of signing and sealing runs through the whole of the apocalyptic literature. It is found as early as Ezekiel 9. There, God is making preparations for judgment. The day of the visitation of the city is at hand. But first the Lord calls to “the man clothed with linen who had the writer’s ink-horn by his side” and says to him, “Go through the midst of the city, through the midst of Jerusalem, and set a mark on the middle of the foreheads of the men who sigh and cry over all the abominations that are done in its midst.” Only after that does he give those who are charged with the judgment the command to begin, adding, “But do not come near any man on whom is the mark” (Ezekiel 9:4 and 6) ... In the Apocalypse of John the notion of the sealing stands prominently in the foreground. The locusts receive power to hurt only those who have not the seal of God on their foreheads (Revelation 9:4, 5). The beast (Revelation 13:16ff.) compels men to bear his mark; only those who will not accept it are to reign with Christ (Revelation 20:4). But the chosen hundred and forty-four thousand bear the name of God and the name of the Lamb upon their foreheads (Revelation 14:1) ..."
Schweitzer, Albert "The Solution of Thoroughgoing Eschatology" in Dunn, James D. G., and Scot McKnight (eds.) The Historical Jesus in Recent Research (pp. 6-49) Eisenbrauns, 2005