na guror adhikaṃ tattvaṃ

Guru stotram

na guror adhikaṃ tattvaṃ

na guror adhikaṃ tapaḥ

tattva jñānāt paraṃ nāsti

tasmai śrī gurave namaḥ

There is no higher truth than the Guru, no higher penance than (service to) the Guru, there is nothing higher than Realization of the Knowledge of the truth imparted by the Guru. My salutations to such a Guru, who is himself that very timeless truth (and who has taken a form to bless his disciples like us with real knowledge).

this sthothra, is a flow of heart ,

the shishya,  having had the glimpse of all-fulfilling absolute within ,

ie, his internal guru having been lit

----as a result of practicing the instruction taught by his guru,----

----and  having accessed the source of every thing worthwhile,within, ---

 ,

has become  immersed in the ecstasy,  is now seeing the  transcendental reality of his external guru

as nothing but the same as the internal guru, the gyan jyothi

and singing the glory of both together , the plane of reference becoming transparent, non existent

Tattvam, tat tvam , that you
ie, the essence, what that exists basically, fundamentally,and really,
ie truth of existence of you / truth of existence of individual ,
or simply the truth

when shishya experiences this truth, and since he could experience only with the help of guru ,

and comes to know that himself, and external guru are nothing but truth , he simply utters what he felt
that is guru himself is the truth
hence there is no greater thing as guru
so no greater thing than guru guidance
so na guror adhikam tattvam

applicable for external guru and internal guru both , they both merged, merged with his own self in essence, the truth

hence
My salutations to such a Guru, who is himself that very timeless truth, and who has taken up a form to bless his disciples like us with real knowledge.

Devotee goes from form to formless,
from visible to invisible,
from relative to absolute,
from earthly to heavenly
from apara to para

we see this transparent walk in the devotional songs of saints ,
and---- the reader too ----experiences such ecstasy
in reading / listening such expressions from great souls