Shruti :– “आहारशुद्धौ सत्त्वशुद्धिः सत्त्वशुद्धौ ध्रुव स्मृतिः—When the food is pure, then the inner-sense gets purified; on the purification of the innersense, memory (of the soul’s perfection) becomes steady.”
Ahara means the sense-perceptions
Everyone knows by experience that impure food weakens the power of receptivity of the Indriyas or makes them act in opposition to the will. It is a well-known fact that indigestion distorts the vision of things and makes one thing appeal as another, and that want of food makes the eyesight and other powers of the senses dim and weak. Similarly, it is often seen that some particular kind of food brings on some particular state of the body and the mind. This principle is at the root of those many rules which are so strictly enjoined in Hindu society—that we should take this sort and avoid that sort of food—though in many cases, forgetting their essential substance, the kernel, we are now busy only with quarelling about the shell and keeping watch and ward over it.
Râmânujâchârya asks us to avoid three sorts at defects which, according to him, make food impure.
The first defect is that of the Jâti, i.e. the very nature or the species to which the food belongs, as onion, garlic, and so on. These have an exciting tendency and, when taken, produce restlessness of the mind, or in other words perturb the intellect. The next is that of Âshraya, i.e. the nature of the person from whom the food comes. The food coming from a wicked person will make one impure and think wicked thoughts, while the food coming from a good man will elevate one’s thoughts. Then the other is Nimitta-dosha, i.e. impurity in food due to such agents in it as dirt and dust, worms or hair; taking such food also makes the mind impure. Of these three defects, anyone can eschew the Jati and the Nimitta, but it is not easy for all to avoid the Ashraya.
This is the part of the writings on Shruti and Ramanuja.