[INDOLOGY] Dharmasastra quotation on upanayana

[Martin Gansten]

Balabhadra in his Hāyanaratna quotes an unnamed text on the preferred 
time of upanayana. The MSS I have seen all give the quotation as:

aṣṭavarṣaṃ brāhmaṇam upanīyayet ṣaṣṭhe ’nnādyakāma iti

The printed text cleans this up as follows:

aṣṭame varṣe brāhmaṇam upanayet ṣaṣṭhe ’nnādyakāma iti

-- but I don't know whether this corrected version exactly matches any 
actual text. Any help in placing the quotation would be much appreciated.

Martin Gansten