The Mandukya Upanishad with Gaudapada’s Karika and Shankara’s Commentary
Kārikā, verse 1.21
मकारभावे प्राज्ञस्य मानसामान्यमुत्कटम् ।
मात्रासंप्रतिपत्तौ तु लयसामान्यमेव च ॥ २१ ॥
makārabhāve prājñasya mānasāmānyamutkaṭam |
mātrāsaṃpratipattau tu layasāmānyameva ca || 21 ||
21. Of the identity of Prājña and M (म) the clear reason is the common feature, i.e., they both are the ‘measure’. The other reason for such identity is another common feature, namely, all become one in both Prājña and M.
Regarding the identity of Prājña, and M the plain common features are that both of them are the ‘measure’ as well as that wherein all merge.