This is a quote from the book "Animal Farm" by George Orwell
...

They limped into the yard. The pellets under the skin of Boxer’s leg smarted painfully. He saw ahead of him the heavy labour of rebuilding the windmill from the foundations, and already in imaginat ion he braced himself for the task. But for the first time it occurred to him that he was eleven years old and that perhaps his great muscles were not quite what they had once been.

But when the animals saw the green flag flying, and heard the gun firing again — seven times it was fired in all — and heard the speech that Napoleon made, congratulating them on their conduct, it ...

read full book block explorer