肇論新疏 1.291

1.291

不無者，夫無則湛然不動可謂之無。萬物若無則不應起，起則非無，以明緣起故不無也。

"As for not non-existent: if non-existence were serene and unmoving, it could be called non-existent. If the myriad things were non-existent, they should not arise; since they arise, they are not non-existent. This clarifies that because they arise dependently, they are not non-existent."