nidrā: what the term means and how it is translated

Charaka SamhitaSutrasthana 21 (Ashtauninditiya):Standard (Trikamji, as printed on carakasamhitaonline.com) 21/35; Kaviratna prints his aphorism number 31 after this passage · checked against the source

When, the mind being fatigued, they that are the souls of action (viz., the senses), becoming fatigued, recede from their objects, it is then that one sleeps.

The definition of when sleep occurs. Sanskrit seen at carakasamhitaonline.com/index.php/Ashtauninditiya_Adhyaya: यदा तु मनसि क्लान्ते कर्मात्मानः क्लमान्विताः | विषयेभ्यो निवर्तन्ते तदा स्वपिति मानवः||३५||. Kaviratna's footnote (his own, not the text): 'Sleep, according to this definition, is a total suspension of mental faculties as also the senses'.

Charaka SamhitaSutrasthana 21:Standard 21/36; Kaviratna prints 32 after it · checked against the source

Happiness and misery, growth and waste, strength and weakness, virility and sterility, knowledge and ignorance, life and death, all depend upon (judicious and injudicious) sleep.

Effects dependent on sleep. Sanskrit seen: निद्रायत्तं सुखं दुःखं पुष्टिः कार्श्यं बलाबलम्| वृषता क्लीबता ज्ञानमज्ञानं जीवितं न च||३६||. Note '(judicious and injudicious)' is Kaviratna's parenthetical gloss, not in the Sanskrit.

Charaka SamhitaSutrasthana 21:Standard 21/37; Kaviratna prints 33 after it · checked against the source

Sleep, when indulged on improper occasions or in excess, or not at all, does not contribute to either happiness or longevity, for it is even like the Last Night.

Akāla, atiprasaṅga and absence of sleep as harmful. Sanskrit seen: अकालेऽतिप्रसङ्गाच्च न च निद्रा निषेविता| सुखायुषी पराकुर्यात् कालरात्रिरिवापरा||३७||.

Charaka SamhitaSutrasthana 21:Standard 21/58-59; Kaviratna's printed numbers OCR as '64' and '*66' which cannot be right given his 31-34 above; his actual printed numbers here were NOT reliably established · checked against the source

Sleep arises from Tamas, from phlegm also, from the weariness of both mind and body, from hurts and wounds; it is induced also by disease; it arises also from the very nature of Night. [...] Amongst these, that sleep which arises from the nature of Night is called the Nurse of all creatures. The sleep that arises from Tamas is regarded as the root of evil. The sleep that arises from the other causes is regarded as due to Disease.

The six/seven-fold classification of sleep and bhūtadhātrī ('Nurse of all creatures'). Sanskrit seen: तमोभवा श्लेष्मसमुद्भवा च मनःशरीरश्रमसम्भवा च| आगन्तुकी व्याध्यनुवर्तिनी च रात्रिस्वभावप्रभवा च निद्रा||५८|| रात्रिस्वभावप्रभवा मता या तां भूतधात्रीं प्रवदन्ति तज्ज्ञाः| ...||५९||.

Charaka SamhitaSutrasthana 11 (Tistraishaniya):Standard 11/35; Kaviratna's number for this paragraph OCRs as '36' (the preceding list aphorism carries '*29'), so his number is uncertain · checked against the source

The three stays (of the body regarded as a column) are eating, sleep, and restraint of the senses.

Sleep (svapna) as one of the three upastambhas. Sanskrit seen at carakasamhitaonline.com/index.php/Tistraishaniya_Adhyaya: त्रय उपस्तम्भा इति- आहारः, स्वप्नो, ब्रह्मचर्यमिति [35]. Note the Sanskrit uses svapna, not nidrā; Kaviratna renders brahmacarya as 'restraint of the senses' and footnotes that 'upastambha' means the stays which support a column.

Sushruta SamhitaSharirasthana IV (Garbhavyakarana):Bhishagratna's own section numbers, NOT Sanskrit verse numbers (vol. 2, Sarira-sthana ch. IV, pp. 149-151): 'Sleep is the illusive energy of God...' opens the paragraph he closes '33-34'; 'Sleep is the offspring of Tamas... fundamental law of Nature' is inside the Memorable Verses he closes '35'; 'Day sleep is forbidden...' opens the paragraph he closes '36'. His 37-39 (do not sleep by day, live a hundred years, habituation) and 40 hold none of the quoted text. Sanskrit numbering (sa.wikisource सुश्रुतसंहिता/शारीरस्थानम् ch. 4, agreeing with easyayurveda): 4/31 heart enveloped by tamas, all beings sleep; 4/33 निद्रां तु वैष्णवीं पाप्मानमुपदिशन्ति... (prose: vaishnavi, tamasi, temperaments, vaikariki) = Bh 33-34; 4/34-37 verses, of which 4/35 निद्रा हेतुस्तमः सत्त्वं बोधने हेतुरुच्यते | स्वभाव एव वा हेतुर्गरीयान् परिकीर्त्यते = the 'offspring of Tamas... law of Nature' sentences (Bh 35); 4/38 सर्वर्तुषु दिवास्वापः प्रतिषिद्धोऽन्यत्र ग्रीष्मात्... (prose) = Bh 36; 4/39-41 = Bh 37-39, not quoted. · checked against the source

Sleep is the illusive energy of God (lit.–the all-pervading deity) and naturally has its sway over all created beings. [...] Sleep is the offspring of Tamas and it is the quality of Sattvam that brings on awakening. This is the fundamental law of Nature. [...] Day sleep is forbidden in all seasons of the year, except in summer and in the case of infants, old men, and persons enfeebled by sexual excesses...

Sushruta's account of sleep: vaiṣṇavī, tamas origin, day-sleep rules. Bhishagratna's footnote (his, not the text) cross-references Charaka: 'When the active self of a person, tired in body and mind, loses touch with his worldly affairs, sleep comes to him.'

Sushruta SamhitaChikitsasthana XXIV (Anagatabadha-pratishedha):Sushruta Cikitsa 24/88 (sa.wikisource चिकित्सास्थानम् अध्याय २१-२५ numbering): पुष्टिवर्णबलोत्साहमग्निदीप्तिमतन्द्रिताम् | करोति धातुसाम्यं च निद्रा काले निषेविता ||८८||. Bhishagratna prints no verse numbers; the sentence closes the paragraph he marks '61-65'. · checked against the source

A good sleep (Nidra) enjoyed at the proper time (and for the proper period) tends to improve the growth, strength, vigour and complexion of the body. It increases the power of digestion, removes drowsiness, and restores the natural equilibrium among the different fundamental principles (Dhatus) of the organism.

Benefits of timely sleep within the hygiene chapter.

Ashtanga HridayaSutrasthana 7 (Annaraksha):7/53-68 per easyayurveda.com chapter page; 7/53 reads निद्रायत्तं सुखं दुःखं पुष्टिः कार्श्यं बलाबलम् (parallel to Cha.Su.21/36) · address only, nothing quoted to check

Vagbhata's sleep section. No quotation permitted.