Yāska's Nirukta 13.12

13.12

akṣaram na kṣarati,.na kṣīyate vā akṣayo bhavati/
vācas akṣa iti vā/
akṣo yānasya añjanāt/
tat prakṛti itarad vartana sāmānyāt/
ity ayam mantra artha cintā abhyūhas abhyūḷhah/
api śrutitas api tarkatah/
na tu pṛthaktvena mantrā nirvaktavyāh/
prakaraṇaśa eva tu nirvaktavyāh/
na hy eṣu pratyakṣam asty anṛṣer atapaso vā/
pārovaryavitsu tu khalu veditṛsu bhūyas vidyaḥ praśasyo bhavati ity uktam purastāt/
manuṣyā vā ṛṣisu utkrāmatsu devān abruvan/
ko na ṛṣir bhaviṣyati iti/
tebhya etam tarkam ṛṣim prāyacchan mantra artha cintā abhyūham abhyūḷham/
tasmād yad eva kiṃca anūcānas ahyūhaty ārṣam tad bhavati/

The imperishable (*akṣara*) does not stream (*na kṣarati*), or it does not diminish (*na kṣīyate*), or it is imperishable (*akṣaya*).
Or it is the axle (*akṣa*) of speech.
The axle of a vehicle [is so called] from smearing (*añjana*).
The other [meaning of *akṣa*, the die] has that as its origin because of the common property of rolling.
Thus this investigation and reasoned inference regarding the meaning of the mantras has been inferred,
both from sacred tradition and through reasoning.
Mantras, however, are not to be explained in isolation;
rather, they are to be explained according to their context.
For among these [mantras], there is no direct perception for one who is not a seer or without ascetic practice.
Indeed, among knowers who discern the higher and the lower, the one of greater knowledge is praised, as was stated before.
When the seers were departing, men said to the gods:
"Who will be a seer for us?"
To them they gave this seer, reasoning: the investigation and reasoned inference regarding the meaning of the mantras, fully inferred.
Therefore, whatever an educated scholar infers by reasoning, that belongs to the seers.