The father said: 'Taste it from the surface of the water. How is it?' The son replied: 'It is salt.' 'Taste it from the middle. How is it?' The son replied: "It is salt.' 'Taste it from the bottom. How is it?' The son replied: 'It is salt.' The father said: 'Throw it away and then wait on me.' He did so; but salt exists for ever. Then the father said: 'Here also, in this body, forsooth, you do not perceive the True (Sat), my son; but there indeed it is.

In plain words: The son tastes the water from the top, the middle and the bottom, and it is salty everywhere. The father explains that the True (Sat) is in the body in the same way: you cannot see it, but it is really there everywhere.