A man from Cocanada [Kakinada] asked:

‘My mind remains clear for two or three days and turns dull for the next two or three days; and so it alternates. What is it due to?’

Sri Ramana Maharshi:

It is quite natural; it is the play of brightness (sattva), activity (rajas) and darkness (tamas) alternating. Do not regret the tamas; but when sattva [peace] comes into play, hold on to it fast and make the best of it.

Taken from Talks with Sri Ramana Maharshi, Talk number 52

Tom: here the advice is clear; when you are peaceful, take advantage of this peace and make the most of it – abide in this peace and know yourself to be beyond all.