Rasaprakashasudhakara 5.14

5.14

pācitaṃ doṣaśūnyaṃ tu śuddhimāyāti niścitam
tathāgnau paritaptaṃ tu niṣiñcet saptavārakam //

cooked [thus], free from blemish, it certainly attains purification. / Likewise, heated thoroughly in fire, one should quench it seven times;