Agnipurana 210.6

210.6

dhānyadroṇasahasreṇa uttamo 'rdhārdhataḥ parau /
uttamaḥ ṣoḍaśadroṇaḥ kartavyo lavaṇācalaḥ //

The highest [mountain of grain] is [made] with a thousand droṇas of grain; the other two are successively halved. / The highest mountain of salt should be made with sixteen droṇas;