Meditations 6.33

Neither the labor which the hand does nor that of the foot is contrary to nature, so long as the foot does the foot's work and the hand the hand's. So then neither to a man as a man is his labor contrary to nature, so long as it does the things of a man. But if the labor is not contrary to his nature, neither is it an evil to him.

Marcus Aurelius, Meditations 6.33, translated by George Long

For hand or foot to feel pain is no violation of nature, so long as the foot does its own appointed work, and the hand its own. Similarly pain for a man, as man, is no unnatural thing so long as he does a man's appointed work. But, if not unnatural, then is it not an evil either.

Marcus Aurelius, Meditations 6.33, translated by C. R. Haines