Srimad Bhagavad-Gita :
Chapter-4. ( Jnana-karma-sanyasa-yogam )
yajnasishtamrtabhujo yanti brahma sanatanam,
nayam lokostyayajnasya kutonyah kurusattama.
yajna sishtamrta bhujh = those who take in (eat ) the remnants of such yajna as nector;
sanatanam brahma yanti = do obtain the Supreme Eternal position;
kuru sattama = O Arjuna the best among Kurus ( Kuru dynasity );
ayajnasya = one who does not perform yajna;
ayam lokah nasti = this world is not for him;
anyah kutah = where any other worlds thereafter.
Before Lord Krishna spoke of the merits of performing yagna or offerings of worship to propitiate the Supreme Lord. Now He will speak of the demerits accrued by failure to perform yagna. The key word is ayagnasya which means for one who does not perform yagna. Without performing yagna in one of the 12 previously mentioned ways then even the meager joys of this world are not available. If the pleasure of mortals in this world which is very limited is unavailable to those who do not perform yagna then how can one ever attain the higher planetary systems where pleasure is abundant and unlimited.
Having performed yagna or offerings of worship that are not prohibited by the Vedic scriptures and after duly propitiating the Supreme Lord. Those who partake of the sanctified food remnants that is leftover which is ambrosial nectar they become spiritualised and attain by wisdom realisation of the eternal Brahman or the spiritual substratum pervading all existence. But for those who ignore or neglect to perform yagna their defect is being pointed out that in this material world which is full of the three fold miseries of old age disease and death there will be no chance of happiness for them. So there is no need for such offenders to even think for enjoyment in the heavenly spheres. Lord Krishna is indirectly stating that for one's ultimate well being one must perform yagna as a way of life without reservation.
By diminishing the intake of food the influence of the senses are greatly reduced due to weakness of body. The speech is also so diminished as well. Knowing that the senses and tongue which governs both eating and speaking are all subservient to the mind as revealed in the Vedic scriptures, one of controlled mind should only eat what has been ordained and sanctified in yagna or offerings of worship to the Supreme Lord according to the injunctions of the Vedic scriptures otherwise there is no hope for redemption in this world or the next.
Due to yagna and propitiation to the Supreme Lord are the restraint of the senses achieved. By considering that such efforts are the sole purpose of existence one should wholeheartedly engage in yagna without reservation. One should consider one's life as the oblation offered to the Supreme Lord in full surrender following the injunctions recommended in the Vedic scriptures. In the Brahma Vaivartaka Purana it states that one should realise the Supreme Lord as the yagna and propitiate Him with body, mind and words. When the Brahman or the spiritual substratum pervading all existence has been perceived then the relation between the performer, the activity performed, the recepient of the performance and the result of the performance are all factually not separate from the Supreme Lord one will then experience the actual presence of the Supreme Lord everywhere in all situations.
That person who does not perform yagna or offerings of worship to propitiate the Supreme Lord and who does not perform the regular and occasional duties as prescribed in the Vedic scriptures according to varnasrama or their rank and station in life. Such a person derives absolutely no benefit for receiving a human existence in this world. They have wasted a very precious opportunity as a human birth is very difficult to receive and humans are the only species on the Earth with freewill and the power to reflect on the Supreme. All the goals which humanity aspires for will also allude them for without following the ordinances of the Vedic scriptures which bequeath promotion in the material worlds how can one who never performs yagna even on the level of the food they eat ever expect to be promoted to the heavenly spheres or ever become qualified for the ultimate achievement of moksa or liberation from the cycle of birth and death in the material existence. Moksa is the true goal of all human endeavour and real purpose of human existence. The divine discourse of the Bhagavad-Gita is all about moksa which is the eternal summum bonum or greatest good eternally for all humanity.
To be continued ....