The Compendium of Caraka 3.7.26_2

3.7.26_2

sa yadā jānīyādviramati śabdaḥ, praśāmyati ca phenaḥ, prasādamāpadyate snehaḥ, yathāsvaṃ ca gandhavarṇarasotpattiḥ, saṃvartate ca bhaiṣajyamaṅgulibhyāṃ mṛdyamānamanatimṛdvanatidāruṇamanaṅguligrāhi ceti, sa kālastasyāvatāraṇāya/

When he knows that the sound ceases, the foam subsides, the oil becomes clear, the characteristic smell, color, and taste are produced, and the medicinal paste, rolled between two fingers, turns neither too soft nor too hard, and does not stick to the fingers—that is the time for taking it down.