The essential conditions to develope jhana is withdrawal from
our senses and having one pointedness.
A very trained person can sit in a very noisy environment and not
become affected by the noise at all. Do you know if you reach
higher jhanas, even if someone chops off your hand, you will not be
affected at all? 1st Jhana maybe not so powerful yet. Well, that is
how strong the one pointedness of jhana is.
As for eating, best is if you can eat vegetarian meals as it does
help in meditation, many have said. Otherwise (just as any Buddhist
should), eat the 5 clean sources of meat:
(1) That he did not slaughter the animal personally
(2) That he did not instruct others to slaughter
(3) That the slaughter was not committed for his sake
(4) That he did not witness the slaughter
(5) That he did not hear the cries associated with the
slaughter
Also try to avoid eating pungent herbs: garlic, chives, leeks,
onions, and asafoetida. It can cause passion and anger and distrupt
meditation.
A definite No is Alcohol. My dharma teacher tells us that she
unknowingly drank some Ginseng wine, and for a long time was unable
to return to the previous stable state of samadhi. Sangha also have
similar experience, his friends put alcohol into his drink without
telling him, and then for quite some time was unable to do jhana or
vipassana practise, like a helpless baby.
Back to First Jhana,
First Jhana
Once Access Concentration has been established, you now induce the
next factor of the First Jhana. This third factor is called Piti
and is variously translated as delight, euphoria, rapture and
ecstasy. By shifting your attention from the meditation subject to
a pleasant sensation, particularly a pleasant physical sensation,
and doing nothing more than not becoming distracted from the
pleasant sensation, you will "automatically" enter the First Jhana.
The experience is that the pleasant sensation grows in intensity
until it explodes into an unmistakable state of ecstasy. This is
Piti, which is primarily a physical experience. Physical pleasure
this intense is accompanied by emotional pleasure, and this
emotional pleasure is Sukha (joy) which is the fourth factor of the
First Jhana. The last factor of the first Jhana is Ekaggata
(one-pointedness of mind). Like Sukha, this factor arises without
you doing anything, and as long as you remain totally focused on
the physical and emotional pleasure, you will remain in the first
Jhana.
As far as I have been able to determine, based on my own
experience, the entry into the first Jhana from a physiological
perspective proceeds something like this:
1. You quiet your mind with the initial and sustained attention to
the meditation subject. I suspect that brain wave activity shows a
noticable decrease during Access Concentration.
2. By shifting your attention to a pleasant sensation, you set up a
positive reinforcement feedback loop within your quiet mind. For
example, one of the most useful pleasant sensations to focus on is
a smile. The act of smiling generates endorphins, which make you
feel good, which makes you smile more, which generates more
endorphins, etc.
3. The final and most difficult part of entering the First Jhana is
to not do anything but observe the pleasure. Any attempt to
increase the pleasure, even any thoughts of wanting to increase the
pleasure, interrupt the feedback loop and drop you into a less
quiet state of mind. But by doing nothing but focusing intently on
the pleasure, you are propelled into an unmistakably altered state
of consciousness.
See also: Mara
