Charak Samhita
चत्वारि नागपुष्पस्य पलान्यभिनवस्य च। द्रोणाभ्यामम्भसो द्वाभ्यां साधयित्वाऽवतारयेत् ॥१६१॥
To this two drona of water should be added and boiled till one fourth remains. The decoction should be strained out through a cloth and cooled.
english translation
catvAri nAgapuSpasya palAnyabhinavasya ca। droNAbhyAmambhaso dvAbhyAM sAdhayitvA'vatArayet ॥161॥
hk transliteration by Sanscript