Anandakanda 1.4.466

1.4.466

tailāvaśeṣaṃ vipacettārabījāni tatra vai /
bhūyo bhūyo drāvayitvā secayedekaviṃśatim //

One should boil down [the liquid] until only the oil remains; silver seeds in it indeed, / melting [them] again and again, one should quench twenty-one times.