Lesson learnt

पूर्वमेव हठयोगो भवता अक्रियत वेति वृद्धमपृच्छम् |

तस्य उत्तरमासीत् किञ्चित् उच्चैर् वदतु 

यदा भवान् संस्कृतभाषायां वदति तदा भवान् स्वमुखम् अपावृणोतु 

किन्तु योगस्य कुशलशिक्षको भविष्यतीति ||

I asked the old man," before was haThayoga ever done by you."
His reply was,"speak louder please, whenever you speak in the language of Sanskrit, then you must open your mouth, however you will become a good teacher of yoga."