SandhyA has to do with sandhi i.e conjunction. This time is considered very important by the seers for spiritual endeavors. Sandhyavandanam is the nityakarma or daily practice recommended in shastras.
The time of sandhyA is the sandhi or junction between two times i.e dawn is the junction of night and day and dusk is the junction of day and night. These events occur due to rotation of earth and positions of Sun in the sky. Hence Sun worship is the key part of sandhyA. Noon time is also considered for the same reason. One can maximize the results of spiritual practices during these timings.
Apart from three or trikaala sandhyAs. Some tantric traditions also have something called turiya sandhya or fourth sandhya which is during the midnight. However this is not done by the commoners.
In Dhanurveda (the Science of archery) there are two kinds of arms;
Astra and Shastra. The astra shot would destroy the substance on which
it is aimed at (astra prayoga). There is an astra that the Brahmins
have to shoot everyday to destroy the evil. When we say astra prayoga
we have shoot a weapon. What is that weapon? We throw water to destroy
“the evil that is manifested in us; to get rid of sins and impure
thoughts; to wipe the dust of bonds, covering the knowledge and reveal
the true self; for Knowledge to shine like Sun”. This astra prayoga
has to be done three times a day. While we try to do a hard work we
say hold your breath and do it. That is exactly what
we do in Sandhyavandanam by offering Argyam (throwing water).
2. When some one is doing a work sincerely we say (in Tamil) that he is performing holding his breath. So this work of destroying evil
in us has to be done holding the breath. If we do this everyday as
prescribed the impure thoughts would go away. We hold the breath to do
this. So we say “Pranan Ayamya”(hold the breath)”. We do not say
“Nasikam Ayamya (hold the nose)”.
3. What ever work we do we must concentrate. So is the case when we do Asyta Prayoga using water as Astra. We should hold breath for
getting concentration. If we hold the breath how does it hold the mind
from wandering? When the mind is still, breathing stops. When we
experience immense happiness or unbearable sorrow or greatly excited
our breathing stops for a moment; the mind is still. Then it runs
fast. We do not stop breathing voluntarily. When breathing stops mind
is still and vice versa.
4. When we do Argya pradanam we should do it with concentration. Pranayamam helps to concentrate. Pranayamam is yoga that has to be
done for a long period of time with under teacher and it is very
difficult. We normally do 10 pranayams at a time; sometimes we do
three as per procedure. Had we been doing pranayams from the date of
Upanayanam we all would have been Yogeeswaras. What ever we do we have
to do properly; is it not? We must hold breath for 30 seconds in one
Pranayamam. Need not do for more time. It must be done suitable to
individual’s health. If Pranan stops mind would be still. If this is
achieved the water we give as Argya is the Astra.
5. Every action in sandhyavandanam is an offering to Parameswara. Astra prayoga of Argya should be done. Then Gayatri japam has to be
done. Pranayama should be done as many times as possible, but not
much. We must do Sankalpa, Marjanam, Prasanam, Punar marjanam, Argya
Pradanam, Japam, Strotram, Abhivadanam saying that I do all this to
get blessings of Parameshwara. This is know as sankalpa. Marjanam
mantra to be said and water to be sprinkled on head. (first five
mantras on head, sixth on feet and seventh on head). Pranayamam is
the main activity in the entire sandhyavandanam. All three times of
the day Pranayamam to be done. It should be done only prescribed
number of times; excess may cause discomfort unless done under
supervision of a learned teacher. But daily Pranayamam has to be done
by everyone (including one is ill) everyday there will no discomfort
at all.
6. We do sin by thought, speech, and body. We have to get rid of the reaction arising out of these sins. So we do karma to get rid of
these sins through the Sandhyavandanam. We utter mantras (speech) do
gayathri japam (thought), do marjanam and others (bodily actions).
Apart from this Sandhyavandanam is also a form of Bakhti yoga and
Gnyana yoga.
7. Persons who do sandhyavandanam must have individual vessels. Sandhyavandanam has to be done using those vessels. Pranayamam must be
definitely done. Everything to be done as an offering to Eswara
(Eswararpanam). Sandhyavandanam should not be done hurriedly.
8. Several men rose to the level of Maharishis only because they did sandhyavandanam regularly and perfectly. Gayathri japam is being
done from the day of the Maharishis in whose lineage we have been born
(whom we prostrate saying Abivadanam every time we do Sandyavandanam).
It is ones duty to observe and do what one is expected to do
everyday, at least to honour the rishis in whose lineage we have come
from. There have been several rishis after the first rishi. In each
gotram the number of rishis are mentioned;three rishis, five rishis ,
seven rishis etc. This confirms that there were that many rishis in
that gotram. Srivatsa gotram had five rishis.
9. One should not break the continuity of the great lineage. One should perform sandhyavandanam three times a day along with Pranayamam
with sincerity, with out loss of mantra (pronunciation) uchranam, with
total surrender of action to Parameswara with Bakhti and understanding
the meaning of each mantra and Prayoga.
Gayathri Japam
1. The meaning of the word “Gayathri” is that whosoever sings her glory they will be protected. Singing means to utter Her name with
devotion and Bhakti. One who sings Gayathri mantra with devotion and
bhakti would be ever protected. That is why the manra avquired the
name “Gayathri”.
2. In Veda it is said that “Gayathri chandasam matha” which mean that Gayathri is mother of all veda mantras. Chandas means Veda. As
per the Shastras the foremost important part of any work is to keep
the body clean without decline in mantra shakti. “ deho devalayaha
prokto jivaprokthaha sanathanaha”.
3. The body is a temple. Jiva is easwara form (easwara roopa). Unclean matter should not taken to the body. Meat, Tobacco and such
unclean matter should not be taken to the body (a temple). It is know
that temple should not be visited when we are not clean. Similarly
importance is attached for cleanliness of the body.
4. Body has energy derived from meditation and mantra japam. Adding undesirable material to the body would deteriorate the wellness
of the body and weaken the energy. There is a difference in up keeping
of house and temple. The restrictions on cleanliness are more severe
for temple than for a house. Similarly some bodies are expected to be
cleaner than others. Brahmana bodies have to be maintained as clean as
temple because the body is purified by constant mantra japam and
energy. These Brahmana bodies have to protect the Veda mantras and
hence they have to be always maintained pristine pure. No impurities
should be added to the body by consuming unwanted materials. It is the
foremost duty of Brahman to preserve Vedas and through that do well to
the welfare of all species. As he has to do this a Brahmana is bound
by many restrictions in his action and expected to observe strict
discipline. He can not think others are doing why not I? He can not
ask others are consuming certain unclean materials why not I? He can
not think others are having certain bodily pleasures why restriction
for me? Bramhana’s body is not for enjoying pleasure but for
preserving and protecting the Vedas. That is the reason we spend
money and perform Upanayanam. If the body is kept clean like a temple
and maintain discipline for everyone would be fine (sowkyam).