1 Nephi 17:41

And he did straiten them in the wilderness with his rod;

for they hardened their hearts, even as ye have;

and the Lord straitened them because of their iniquity.

He sent fiery flying serpents among them;

and after they were bitten

he prepared a way that they might be healed;

and the labor which they had to perform was to look;

and because of the simpleness of the way, or the easiness of it,

there were many who perished.