Explain the story Father Byrne told of eternity.

During catechism instruction, Father Brynes asked students how long eternity was. They knew it was for a long time but no one could explain how long. The father used an anecdote that when a little bird moves a mountain of sand, one grain at a time, across an ocean, that is only the first day of eternity. The children got the idea and understood that eternity is for a long, long, long time.