Ramayana
यं समाश्रित्य जीवन्ति फेनपाः परमर्षयः । अमृतं यत्र चोत्पन्नं स्वधा च स्वधभोजिनाम् ॥ 7-23-23 ॥
Resorting to whom the supreme sages who drink only foam subsist; in whom the nectar of immortality was produced, and the svadha-offering of those who feed upon svadha;
english translation