Failure to be Initiated: If his time for initiation has lapsed, a man should live observing the rules of a student of the three Vedas for one season and then undergo initiation. For a year thereafter he should take a daily bath, after which time he may receive vedic instruction.
Apastamba Dharmasutra Prasna 1 Sutras 28-31
What are these rules that a student of the three vedas follows?
Acc. to Apastamba this is the penance for a late Upanayanam.
