Essence of j1🌘 First Jhāna

From studying every reference to STED 4j🌕 formula, and examining what happens right before first jhāna, we can see the pattern.

Before one has mastered the skill of stopping internal dialogue at will, entering the 👑😶 noble silence of 2nd jhāna where V&V💭 are shut off and replaced by subverbal awareness and investigation of S&S🐘💭 , one first has to:

0. Understand and memorize the 7sb☀️ awakening factors. Especially SN 46.3. Every meditation technique, including those that use V&V skillfully in first jhana, rely on that as the underlying structure. The 4 jhānas are the 6th factor, samādhi-sambojjhanga, shown clearly in DN 2.

1. Understand the danger, the dukkha, and disadvantages of 5kg and 5niv⛅ . V&V💭 has a large role in accomplishing this, so one should not be too greedy and shoot for 4th jhāna or 2nd jhāna before mastering first jhāna and how to use first jhāna's V&V💭 skillfully.

2. Before one can completely shut off internal dialogue of V&V💭 , one first has to learn how to replace askusala/unskillful v&v with skillful v&v, and then attenuate the v&v so it doesn't block passaddhi/pacification awakening factor and the pīti & sukha (rapture and pleasure) of first jhāna. See MN 19 and vitakka & vicāra in first jhāna.

2b. Remember what 'gradual' means. You have to walk before you can run, and you have to first get rid of akusala vitakka and replace them right away with kusala vitakka (section 2). There's even samādhi in 3 ways to describe an intermediate stage between first and second jhāna for how vicāra is used before being dropped (or more accurately, sublimated). Living beings spent entire lifetimes thinking all the time, the Buddha designed a gradual training system, and he doesn't expect you completely eliminate v&v all at once.

3. The way to stabilize and prolong first jhāna, is by learning how to use V&V💭 skillfully to direct the mind to inspiring themes to stoke the fire of first jhāna and keep it burning. Suttas such as MN 20, SN 47.8, SN 47.10, SN 46.3, AN 6.10, AN 8.30 are a few such examples.

4. How do you know if you are on the right track for first jhāna? The most important part of first jhāna is not samatha kung fu, but the correct understanding of section #1 (seeing dukkha in 5kg...). The internal test to verify oneself (MN 14), do you genuinely reject 5kg 5 cords of sensual pleasure because rapture & pleasure of first jhāna is much more enticing not just because of the bliss, but because you truly see it doesn't have the drawbacks of 5kg? A samatha kung fu expert who can sit for 5 hours straight and blank their mind out, but then they still lust after sex and 5 cords of sense pleasure, they completely miss the essence of genuine first jhāna. Samatha and Vipassana need to be conjoined and balanced. Genuine EBT jhāna does this.

5. This is why you should be very wary of following non EBT samādhi systems that falsely claim to be genuine jhāna, but tends to segregate samatha from vipassana and overly emphasize samatha kung fu for first jhāna. V&V💭 has an important role to play in this stage of development, and cutting off v&v (by redefining it as 'placing the mind' or 'initial application') is cutting off one's fuel for jhāna (see section 3). How self defeating is that?

Physical side of first jhāna

The above summarises the essentials on the mental side of things.
As far as the physical side, how to pacify (kāya-passaddhi) the body to induce sukha and samādhi-sambojjhanga of first jhāna, see 5🌊, 16🌬️😤‍ especially steps 3 and 4.
Read Jhāna-constipation ⛜🌊 for brutally effective ways to cure jhāna-constipation.