Once I saw mountains angry

Once I saw mountains angry,
And ranged in battle-front.
Against them stood a little man;
Aye, he was no bigger than my finger.
I laughed, and spoke to one near me,
"Will he prevail?"
"Surely," replied this other;
"His grandfathers beat them many times."
Then did I see much virtue in grandfathers --
At least, for the little man
Who stood against the mountains.