From a sinful act committed only once, one may clear himself by repenting for it. From an act committed twice, one may purify himself by vowing never to repeat the act.
विकर्मणा तप्यमानः पापाद् विपरिमुच्यते। नैतत् कार्यं पुनरिति द्वितीयात् परिमुच्यते॥