This part is taken from Various Stories & Tales in “Spiritual Stories” as Told by Ramana Maharshi

Bhagavan narrated the following story to illustrate the distinction between manolaya (stillness of mind) and manonasa (destruction of mind).

A yogi was doing penance (tapas) for a number of years on the banks of the Ganges. When he had attained a high degree of concentration, he believed that to remain in that state for prolonged periods constituted salvation and therefore continued practising it. One day, before going into samadhi (a state of deep concentration), he felt thirsty and asked his disciple to bring some water for drinking from the Ganges; but before the disciple could return with the water, he had gone into samadhi, and he remained in that state for countless years. When he woke up from this experience, the first thing he did was to say, “water! water!”; but there was neither his disciple nor the Ganges in sight.

The first thing which he asked for was water because, before going into deep concentration, the topmost thought in his mind was about water; by concentration, however deep and prolonged it might have been, he had only been able to lull his thoughts temporarily; therefore when he revived consciousness this topmost thought flew up with all the speed and force of a flood breaking through the dykes. If this was the case with regard to a thought which took shape immediately before he sat for meditation, there is no doubt that other thoughts which had taken deeper root earlier would still remain unannihilated. If annihilation of thoughts is salvation, can he be said to have attained salvation?

The moral is that one should not be taken away by the spell of temporary stillness but pursue the enquiry till the last vasana is eradicated.