The Sage no longer differentiates between dualism and non-dualism (advaita), for he does not cognise them as different.
Objective Godhead and Subjective Godhead are Identical
A self that prays, humbly,* to God, and a self that, being no longer personal, is God, are basically the same, so that praying humbly* to God, and being, impersonally, God, are not fundamentally different.
Being oneself, without self, is not different from 'oneself', without self, being 'other'.
That is why, to the Sage, there is no difference between self and other.
Therefore the ultimate understanding of the Sage is: I am no longer an 'I', what that 'I' is-not is all there is, and this is Godhead.
Note: That, also, explains the three degrees of understanding in Buddhism; (1) when mountains and rivers are cognised as such: subject seeing object; (2) when mountains and rivers are no longer cognised as mountains and rivers: object seen as subject only; and (3) when mountains and rivers are once more cognised as mountains and rivers: subject and object seen as not separate. That is why 'the way' is often described as being discrimination between object and subject : so that, temporarily, objects may no longer be cognised as objects.
* 'Humbly' here is not used as the counterpart of 'proudly', for such 'humility' is just negative 'pride'. Humility, metaphysically, implies the absence of any entity to be either 'proud' or 'humble'.