all EBT sutta references to thina middha / sloth & torpor & drowsiness I'm looking to collect all the major sutta references on the 3rd hindrance.
Help me complete the collection:
http://lucid24.org/sted/5niv/5niv3/index.html
What I have so far:
AN 5.78 5 future dangers
AN 5.193 saṅgārava: similes of looking at reflection in bowl of water, 3. Sloth-torpor like water with moss and aquatic plants
AN 7.46 seeing suffering in impermanence
AN 7.61 Pacalāyana: Buddha advises Moggallana with 7 ways to cope: You should have 7 memorized and recite daily.
MN 62 mudita to counter listlessness
MN 70 let only my skin and bones remain... : using vigor to counteract sloth
MN 131 today the effort must be made...: using maraṇa-s-sati 
SN 46.51 Nourishment and starving of Sloth and Torpor
SN 46.53 balancing 7sb☀️ factors
SN 46.55 simile of water covered with moss
Let's restrict the discussion to EBT (early buddhist text, pali, chinese agama, sanskrit, etc.) for now. I'll open up a thread later for Non EBT strategies to deal with sloth later.
Suttas with similes of the 5 hindrances
AN 3.101 simile of 3 levels of gold impurities preventing samadhi and 6ab ⚡☸. 5niv are the 2nd level moderate impurities.
AN 5.23 simile of gold impurities (instead of 'nivarana' calls 5niv 'cittassa upakkilesā') preventing samadhi and 6ab ⚡☸. Also uses keywords from j4 āneñja⚡.
AN 5.51 simile of river split into 5.
DN 2 similes 1. in debt, 2. ill, 3. imprisoned, 4. slave, 5. crossing desert
MN 140 references goldsmith removing impurities, similar to AN 3.101 and AN 3.102, but doesn't call out 5 elements of 5niv by names.
SN 46.33 5 impurities of gold (copper, tin, silver...) make gold (samadhi mind) brittle and unworkable.
SN 46.55 similes for not seeing one's reflection in bowl of water: 1. water is colored with dyes, 2. heated by fire, boiling and bubbling, 3. overgrown with moss, 4. stirred by the wind, 5. murky, muddy
The commentaries follow the Dhammasaṅgaṇī in treating both as mental: thīna as sluggishness of citta, middha as sluggishness of cetasikas. But this is in the context of bhāvanā, in connection with the hindrances. Where the terms are used in non-technical everyday contexts the state may be physical, mental, both or unspecified. I think unspecified is probably the most common.
The word &quot;hīna&quot; is a past participle that's been made into a noun. The rules for forming past participles would allow both thīna and thina as the pp. of the verb thīyati.
As for vīriya vs viriya, it's not that they were once two different words that are now taken to be the same, but that they've always been variant forms of the past participle of the same verb, just as 'dreamed' and 'dreamt' have always been variant past participles of 'dream'.
Note that the sutta doesn't identify the nutriment of thīnamiddha with the five items themselves, but rather with frequent unwise attention (ayoniso­ma­nasikā­ra-­bahu­līkāro) to them. And so the immediate cause is wholly mental.
But as to the five, this is how the Vibhaṅga defines them:


Tattha katamā arati? Pantesu vā senāsanesu aññataraññataresu vā adhikusalesu dhammesu arati aratitā anabhirati anabhiramaṇā ukkaṇṭhitā
paritassitā: ayaṃ vuccati “arati”. Therein what is “tedium”? Tedium,
having tedium, displeasure, being displeased, dissatisfaction, dread
of remote abodes or certain higher skilful dhammas. This is called
tedium.

Tattha katamā tandī? Yā tandī tandiyanā tandimanakatā ālasyaṃ ālasyāyanā ālasyāyitattaṃ: ayaṃ vuccati “tandī”. Therein what is
“apathy”? That which is apathy, being apathetic, mental lethargy,
idleness, being idle, state of being idle. This is called apathy.

Tattha katamā vijambhitā? Yā kāyassa jambhanā vijambhanā ānamanā vinamanā sannamanā paṇamanā byādhiyakaṃ: ayaṃ vuccati “vijambhitā”.
Therein what is “stretching”? That which is twitching, stretching,
bending forward, bending backward, twisting, stretching upwards,
fidgeting of the body. This is called stretching.

Tattha katamo bhattasammado? Yā bhuttāvissa bhattamucchā bhattakilamatho bhattapariḷāho kāyaduṭṭhullaṃ: ayaṃ vuccati
“bhattasammado”. Therein what is “after meal drowsiness”? That which
in one who has eaten is dizziness because of food, fatigue because of
food, feverishness because of food, bodily unfitness. This is called
after meal drowsiness.

Tattha katamaṃ cetaso ca līnattaṃ? Yā cittassa akalyatā akammaññatā olīyanā sallīyanā līnaṃ līyanā līyitattaṃ thinaṃ thīyanā thīyitattaṃ
cittassa: idaṃ vuccati “cetaso ca līnattaṃ”. Therein what is “mental
sluggishness”? That which is indisposition of consciousness,
unwieldiness, drooping, sagging, sluggishness, being sluggish, state
of being sluggish, sloth, being slothful, state of consciousness being
slothful. This is called mental sluggishness. (Vibh. 17:10:1. U
Thittila's translation, with 'restlessness' changed to 'stretching' as
the translation of vijambhitā)


https://legacy.suttacentral.net/en/vb17

And from the Dispeller of Delusion:

The arising of stiffness and torpor comes about through unwise
bringing to mind in regard to boredom (arati) and so on. &quot;Boredom&quot; is
a name for dissatisfaction; &quot;languor&quot; (tandi) is a name for bodily
laziness; &quot;stretching&quot; (vijambhitā) is a name for bending of the body;
&quot;faintness after meals&quot; (bhattasammada) is a name for giddiness after
meals and feverishness after meals. And mental lassitude&quot; (cetaso
līnattaṃ) is a name for the sluggish state of the mind.
Because of employing unwise bringing to mind much in regard to these
[states] beginning with boredom, stiffness and torpor arise.
(Dispeller of Delusion I 335)

So, it seems that arati is wholly mental; tandī is both bodily and mental (the Dispeller of Delusion later defines it as &quot;bodily idleness due to defilement&quot;); likewise vijambhitā, which is later defined as &quot;bodily shifting due to defilement&quot;; bhattasammada is wholly bodily; and cetaso līnattaṃ wholly mental.