By Swami Harshananda
Brahmacārins residing in the gurukulas for learning the Vedas had to observe some vratas or religious vows before commencing the study of certain sections. They were enumerated as four:
They were each of one year’s duration, starting from the age 13 - 16. However, they seem to have been given up in course of time.
- The Concise Encyclopedia of Hinduism, Swami Harshananda, Ram Krishna Math, Bangalore