Revelation 9:4

and they were commanded not to hurt the fruits of the earth, nor any green thing, nor any tree; but those men who have not the seal of God in their foreheads.

2 Corinthians 1:22

and mark'd me with his seal, and given me the earnest of the spirit in my heart.

Revelation 14:1

THEN I looked, and I saw a lamb on mount Sion, and with him an hundred forty and four thousand, having his name and his father's name writ on their foreheads.

Revelation 7:2-3

and I saw another angel ascending from the east, having the seal of the living God: and he cried with a loud vioce to the four angels, to whom it was given to hurt the earth and the sea,

2 Timothy 2:19

however, the foundation of the divine architect is still immoveable, having this inscription, " the Lord discerns who are his." and, " let every one that invokes the name of the Lord, depart from iniquity."

Revelation 20:4

I saw likewise thrones, where persons were seated, to whom the power of judging was given: and I saw the souls of those that were beheaded for the testimony they had given to Jesus, and for the word of God, who had not worshipped the beast, nor his image, nor had received his mark upon their foreheads, or in their hands; and they lived and reigned with Christ a thousand years.

2 Corinthians 12:21

and I am afraid, God will humble me when I come again among you, and I shall bewail many who have formerly sinned, and have not yet repented of their impurity, their fornication, and dissoluteness.

Ephesians 4:30

grieve not the holy spirit of God, by whom you are sealed against the day of deliverance:

2 Peter 2:8-9

for whilst this good man was among them, it daily pierc'd his virtuous soul, to see and hear of their detestable behaviour: this consider'd,

Revelation 13:6-7

and he opened his mouth in blasphemy against God, to blaspheme his name, and his tabernacle, and those that dwell in heaven,

Treasury of Scripture Knowledge

Summary

And the LORD said unto him, Go through the midst of the city, through the midst of Jerusalem, and set a mark upon the foreheads of the men that sigh and that cry for all the abominations that be done in the midst thereof.

General references

Bible References

That sigh

2 Corinthians 12:21
and I am afraid, God will humble me when I come again among you, and I shall bewail many who have formerly sinned, and have not yet repented of their impurity, their fornication, and dissoluteness.
2 Peter 2:8
for whilst this good man was among them, it daily pierc'd his virtuous soul, to see and hear of their detestable behaviour: this consider'd,

General references

Matthew 5:4
Blessed are they that mourn: for they shall be comforted.
Romans 9:2
that I have great heaviness, and continual sorrow in my heart.