Srirama Krishna says that Bhokti-tio Shammadi hai kumbakai and Samadhi by deep devotion an intense devotion to God. There comes times not just once number of times you will have the mind remains absorbed in the hita devata out of sheer love and surrender to the hita Devata. The real meaning of the unflickering light is the light of consciousness is the atman which neither increases nor decreases there is no possibility of its flickering like a flicker.