तद् येनाप्राप्तकं तच्चतुर्गुणेन सीसेन शोधयेत् ॥ कZ_०२.१३.०६ ॥
tad yenāprāptakaṃ taccaturguṇena sīsena śodhayet
That (metal/ore) which is ‘not properly obtained’ (i.e., fails to yield correctly) should be refined by using lead in fourfold proportion.
It creates a repeatable state-standard process so treasury inputs (bullion/metal) meet uniform purity, reducing fraud and variability in minting.