स वै वाचमेव प्रथमामत्यवहत् ; सा यदा मृत्युमत्यमुच्यत सोऽग्निरभवत् ; सोऽयमग्निः परेण मृत्युमतिक्रान्तो दीप्यते ॥ १२ ॥
In plain words
He carried speech alone across first. He is prana; speech alone is the first and principal one—meaning this, in comparison with the other organs engaged in the udgitha rite...
Close to the Sanskrit
He indeed carried speech alone first across—he, prana, speech alone, the first, the principal, meaning this—in comparison to other organs engaged in the udgitha action, saadh...