俱舍論記 8.155

8.155

「又影與光至謂二竝生」者，此約影、光同處破。影、光相違，未曾同處，然鏡影中有光像現。不應於此一鏡面上影與光像二色竝生，既二竝生，知像非實。

"Furthermore, shadow and light [...] claim that the two arise side by side": this refutes based on shadow and light sharing the same place. Shadow and light are mutually exclusive and have never shared the same place; yet within the shadow on a mirror, a bright reflection appears. One should not say that on this single surface of a mirror, the two forms of shadow and luminous reflection arise side by side; since the two appear together, we know the reflection is not real.