Smarana means remembering with the mind. Concentratedly remembering. Just speaking it out with the mouth is of no use. It has to be deeply and concentratedly remembered and spoken with that consciousness – from that Narayana awareness.
What we see in ordinary practice is that when as a routine we recite a sloka or mantra, it becomes only just uttering the words with meaning; it wanders thinking about other things and only the mumbling goes on. If that happens here, if the Narayana name is spoken without the mind remembering the Narayana, it will be a great crime – Maha Dosham.
If misappropriation is a crime between people, is it not a very big crime when what belongs to HIM is misappropriated? Everyday, sannyasi receives namaskara from a number of people. There is a great risk of his saying Narayana becoming a mere routine unless he remains ever vigilant and always awake. Otherwise, he may easily find himself involved in committing Maha-dosha.
That is why I said this rule looks easy to follow; it is not actually easy.
A true sannyasi, a hundred percent sannyasi, has no duties. He has no obligations to fulfil. He does not have to think about the well-being or otherwise of another. In that state, if someone performs namaskara to him, he does not have to think about the welfare of that person. If he starts thinking about that, slowly he will start thinking whether some good happened to that person.