'Fragile' in the Bible

His source of confidence is fragile;what he trusts in is a spider’s web.

The house he builds is as fragile as a moth's cocoon, like a hut that a watchman has made.

“And all the inhabitants of Egypt will know [without any doubt] that I am the Lord,Because they have been [only] a staff made of [fragile] reeds to the house of Israel.

And as the toes of the feet were part of iron and part of clay, the kingdom shall be partly strong and partly fragile.