The works of Ādi Śaṅkarācārya

Bṛhadāraṇyakopaniṣadbhāṣyam

Avatarika

Avatarika

लिप्यत एव बुद्धान्ते ; तदेतदुच्यते—

In plain words

At that boundary where waking gives way to dream, he really does pick up a trace of it — and here is exactly how that is explained —

Close to the Sanskrit

He does indeed become tainted at the boundary of the waking state; this very point is now stated —