Sutra:
67. ithu thAn Samashti vAsakam.
68. jAthyEka vacanam.

Meaning:
67. This makAram that speaks of the Atma, is the akshara that stands for all Atmas.
68. It is in the singular that points to the Atma jAti.

Sri PBA Swami's Sarartha Deepikai:
The makAram in the praNavam is in the singular (Eka vacanam) and therefore stands for one Atma. Therefore, is it correct to say that the bhagavat sEshatvam described before talks about the sEshatvam of only one Atma?

Atmas are divided as Baddhas, Muktas and Nityas and bhagavat sEshatvam is the quality for all Atmas. So, how does that fit into this singular use of the makAram?

Pillai Lokacharya answers that the makAram here is a jAtyEka vacanam. That is, the singular used here stands for the type rather than a single case. For example, if one says "umbrella sold in this shop", it does not mean a single umbrella. Similarly the makAram speaks of the Atma jAti rather than a single Atma. Therefore, it stands for all Atmas.