The definition of a Brahmin , a community of India which is ordained by the scriptures to realize the Self,spend entire lifetime learning the Vedas, teaching people of suitable disposition,perform Fire Rites,do the same for others,nevert others and never save for the morrow,is one ‘who realized the Self’
Yajanam Yaajanam Tathaa
Daanam Pratigraham Chaiva
Adyayanam-Pracctice of reciting the Vedas, with meaning.
I have written on,
Who a Brahmin is and his duties,
History of Brahmins,
Their migration throughout the world,
The important question of what he should eat specifically and whether he should learn only the spritual aspects of the Vedas(Vedangas,a part or limb of the Vedas contain mundane subjects including the Art of Warfare), I have not been able to find.
Excepting the facts that,
He should eat food begotten by Alms,
He must refrain from Non Vegetarian food,
Should not drink,
Not covet other’s property,Aparigraha,
Pray for the welfare of the people,
Must not demand money for services save for what is offered to him.
Yet we find that Brahmins were eating Non vegetarian food,some do even now,
Were drinking till the time when Rishi Aurava/Sukracharya) forbade it ,
Demand Dakshina,Fees for services rendered.
I am now able to find authority on what a Brahmin should eat and what his Life style should be from Mahabharata Yaksha Prasna,where Yudhistra replies to a Yaksha.
A Brahmin should eat on the fifth quarter of the day,
Never rich food,
Live near the banks of Rivers,
Eat vegetables,fruits and Roots grown in a property which is not owned by anyone.
He should know all subjects but practice only spirituality.
The Brahmin has to wake up at four in the morning and bathe in cold water, rain or shine, warm or cold. Then, without a break, he has to perform one rite after another: sandhyavandana, Brahmayajna, aupasana, puja, vaisvadeva and one of the 21 sacrifices. If you sit before sacrificial fire for four days you will realise how difficult it is with all the heat and smoke. How many are the vows and the fasts the Brahmin has to keep and how many are the ritual baths….
…. Other castes do not have to go through such hardships. A Brahmin cannot eat “cold rice”in the morning like a peasant – he has no “right” to it. The dharmasastras are not created for his convenience or benefit, nor to ensure that he has a comfortable life. He would not have otherwise imposed on himself the performance of so many rites and a life of such rigorous discipline. When he has his daytime meal it will be 1 or 2. (On the day of a sraddha it will be three or four). This is the time the peasant will have his rest after his meal under a tree out in the field where he works. And the Brahmin’s meal, mind you, is as simple as the peasant’s. There is no difference between the humble dwelling of the peasant and that of the Brahmin. Both alike wear cotton. The peasant may save money for the future but not the Brahmin. He has no right either to borrow money or to live in style. …
In the “Yaksa-prasna” of the Mahabharata the simple life of Brahmin is referred to:
pancame’ hani saste va sakam pacati svegrhe
Anrni ca’ pravasi ca sa varicara modate
If daytime is divided into eight parts, the Brahmin may have his food only in the fifth or sixth part after performing all his rites. Before that he has neither any breakfast nor any snacks. And what does he eat? Not any rich food, no sweets like almonds crushed in sweetened milk. “Sakam pacati” – the Brahmin eats leafy vegetables growing on the banks of rivers, such areas being no one’s property. Why is he asked to live by the river side? It is for his frequent baths and for the leafy vegetables growing free there and for which he does not have to beg. He should not borrow money: that is the meaning of the word “anrni”, because if he developed the habit of borrowing he would be tempted to lead a life of luxury. Poverty and non-acquisitiveness (aparigraha) are his ideals. A Brahmin ought not to keep even a blade of grass in excess of his needs. …
The Brahmin must be conversant with the fourteen branches of the Vedic lore. He must be proficient even in Gandharva-veda or music and must be acquainted with agricultural science, construction of houses, etc. At the same time he must give instructions in these subjects to pupils from the appropriate castes. His own vocation is the study of the Vedas and he must have no other source of income. …
If the Brahmin is asked, “Do you know to wield a knife? ” he must be able to answer, “Yes, I know”. If he is asked, “Do you know to draw and paint” again he must (be able to) say, “Yes”. But he cannot wield a knife or become an artist to earn his livelihood. All he can do is to learn these arts and teach others the same according to their caste. He is permitted to receive a daksina to maintain himself and he must be contented with it however small the sum may be. The Brahmin’s specialty is his true vocation is Vedic learning.
… The goal of Vedic works is the happiness of all mankind, indeed the happiness of all the worlds (“Lokah samastah sukino bhavanthu”). The sound of the Vedas creates universal well-being, so too Vedic sacrifices. … Brahmins would be committing a sin if they gave up Vedic rituals and earned money by doing other types of work.
Kanchi Paramacharya quoting Yaksha Prasna