The phase viññanam anidassanam has been explained by the pali attakattha and tika. Suan Lu zwa, a Burmese pali scholar writes:
"Tattha viññatabbanti "Viññanam" nibbanassetam namam,.."
"There, to be known specially, so (it is) "Viññanam". This is the name of nibbana."
And Kevatta Sutta Tika further explains the phrase "viññatabbanti" as follows:
"Viññatabbanti visitthena ñatabbam, ñanuttamena ariyamaggañanena paccakkhato janitabbanti attho, tenaha "nibbanassetam namam"ti."
"(To be known specially) means to be extraordinarily known. The meaning is 'to be known in the sense of realization by ultimate wisdom, by noble path wisdom'". Therefore, (the commentator) stated that 'This is the name of nibbana'" Therefore, the term 'Viññanam' in the line of the original Pali verse "Viññanam anidassanam, anantam sabbatopabham .." does not refer to consciousness, the usual meaning of viññanam.
In fact, the same verse includes the following two lines "Ettha namañca rupañca, asesam uparujjhati
Viññanassa nirodhena, etthetam uparujjhati'ti". "Here (in nibbana), nama as well as rupa ceases without remainder. By ceasing of consciousness, nama as well as rupa ceases here." Nibbana does not become a sort of consciousness just because one of its Pali names happens to be Viññanam. In English language, the term 'object' can have different meanings. For example, the term 'object' in visual object has no relation to
the term 'object' in my object of studting Pali."" endquote Suan