The Compendium of Caraka 1.27.200

1.27.200

kaṭu parvatavistāre& madhuraṃ kṛṣṇamṛttike/
etat ṣāḍguṇyamākhyātaṃ mahīsthasya jalasya hi/
tathā 'avyaktarasaṃ vidyādaindraṃ kāraṃ himaṃ ca yat//

It is pungent along mountain expanses, and sweet in black earth: / this sixfold variation is declared of water resting on the earth; / and that rain, hail, and snow from Indra should be known as having an unmanifest taste.