The faith of every man, O Arjuna, accords with his nature, Man is made up of faith; as is his faith, so is he. The threefold austerity practiced with faith by men of balanced mind, without any expectation of reward, is said to be pure.
Scholars who incessantly contemplate on acquiring strength and knowledge should also consider it their moral duty to impart knowledge to the ignorant, so that they can develop their mental faculties. This would automatically lead to the latter’s self-development and spiritual progress.
There are many people who fast, whose fast is nothing but hunger and thirst. There are those whose prayer is no better than wakefulness and hardship. The eating and drinking in case of the former and sleeping in the latter’s case is a far better option.

