The mind remains undetermined in the great Void. Here the highest knowledge is unbounded. That which gives things their thusness cannot be delimited by things. So when we speak of 'limits', we remain confined to limited things. The limit of the unlimited is called 'fullness.' The limitlessness of the limited is called 'emptiness.' Tao is the source of both. But it is itself neither fullness nor emptiness.
Source: Chuang Tzu, 22:6, pp. 182-183
Contributed by: Zaady