Charak Samhita
परिवेष्ट्यकुशैरार्द्रैरार्द्रवृन्तानिशाल्मलेः । कृष्णमृत्तिकयाऽऽलिप्यस्वेदयेद्गोमयाग्निना ॥६४॥
Green stalks of shalmali should be covered with green kusha and tied. This bundle is then smeared with the mud of black soil and placed over cow-dung fire. After the mud is dried up, the stalks of shalmali is removed.
english translation
pariveSTyakuzairArdrairArdravRntAnizAlmaleH । kRSNamRttikayA''lipyasvedayedgomayAgninA ॥64॥
hk transliteration by Sanscript