Charak Samhita
रात्रिस्वभावप्रभवा मता या तां भूतधात्रीं प्रवदन्ति तज्ज्ञाः। तमोभवामाहुरघस्य मूलं शेषाः पुनर्व्याधिषु निर्दिशन्ति ॥५९॥
Natural sleep (sleeping at night) is the best form of sleep. This is also known as Bhutadhatri, or “that which nurses all the living beings." The form of sleep that is caused by tamas is the cause of all sinful acts while the remaining types are observed in specific situations and ailments
english translation
rAtrisvabhAvaprabhavA matA yA tAM bhUtadhAtrIM pravadanti tajjJAH। tamobhavAmAhuraghasya mUlaM zeSAH punarvyAdhiSu nirdizanti ॥59॥
hk transliteration by Sanscript