Emperor Akbar's court was famous for its witty question and answer sessions.
On one of these occasions, the Emperor asked Birbal if there was anything that the sun and the moon could not see. Birbal's reply was 'darkness'. Akbar was pleased.
Next, he asked what was the difference between a truth and a lie. To which Birbal replied that it was the distance between the ears and the eyes because what you see with your eyes is true, but what you hear with your ears is generally false. Akbar was satisfied.
Lastly, Emperor Akbar drew a line on the floor and asked Birbal to shorten it without wiping out the ends.
Birbal drew a longer line below the line drawn by Akbar and remarked that though he had not rubbed off the original line he had definitely succeeded in making it shorter.