Hebrews 10:27

there is only a fearful anticipation of judgment, and a burning indignation which will destroy all opponents.

Hebrews 10:31

It is a fearful thing to fall into the hands of the Living God.

Revelation 6:15-17

Then all the kings of the earth, and the princes, and the generals, and the rich, and the powerful, and every slave and free man, 'hid themselves in the caves and under the rocks' of the mountains;

Treasury of Scripture Knowledge

Summary

That they feared greatly, because Gibeon was a great city, as one of the royal cities, and because it was greater than Ai, and all the men thereof were mighty.

Bible References

They feared

Hebrews 10:27
there is only a fearful anticipation of judgment, and a burning indignation which will destroy all opponents.
Revelation 6:15
Then all the kings of the earth, and the princes, and the generals, and the rich, and the powerful, and every slave and free man, 'hid themselves in the caves and under the rocks' of the mountains;