idam astu sannikṛṣṭe samīpataravarti caitado rūpam
idam astu sannikṛṣṭe samīpataravarti caitado rūpam |
adas astu viprakṛṣṭe tad iti parokṣe vijānīyāt ||
(Nīleśa-vistāra on Aṣṭa-dhyāyī: 1.1.27)
“Know ‘idam’ to be [used] for something nearby, ‘etat’ for something even closer, ‘adas’ for something distant [in view], and ‘tad’ for something unperceived.”