आगमे वैष्णवे विश्वासटिप्पन्यः

Source: TW

The text known as mahopaniShat that come down to us has at least 2 layers. The first section has a notable overlap with the nArAyaNavallI - see in the mahAnArAyaNopaniShat whose recensions are attached to the YV-taittirIya and atharvan traditions. This section as expounds nArAyaNa-paratvam along side a 25 tattva sAMkhya. It is clearly a vaiShNava text with sAMkhyan philosophical foundations overlapping with the ideas presented in the nArAyaNIya section of the Mbh. We believe a text close to this first section was alluded to in the said section of the Mbh.

The subsequent sections IMO are a later accretion. The famous vasudhaiva… comes therein. The tenor of those is distinct and probably composed by distinct authors – e.g., shuka referred to as the teacher in second section. Thus, IMO the 1st section likely comes from the time of the pre-tAntrika pA~NcharAtra. When the later sections were added is unclear but might be decipherable on closer study. A similar composite structure is seen in a shaiva-yoga upaniShat.