A stone which had lain for centuries in a hidden place complained to
Allah that remaining so long in one position was productive of cramps.
"If thou wouldst be pleased," it said, "to let me take a little
exercise now and then, my health would be the better for it."
So it was granted permission to make a short excursion, and at once
began rolling out into the open desert. It had not proceeded far
before an ostrich, who was pensively eating a keg of nails, left his
repast, dashed at the stone, and gobbled it up.
This narration teaches the folly of contentment: if the ostrich had
been content with his nails he would never have eaten the stone.