Praudhamanorama p203

p203

[On] 'rāyo hali' (Pāṇini 7.2.85): masculine gender [is established] from Amara's 'artha, rai, and vibhava also [are masculine]', and from usages such as 'saṃrāyā bhūyasāsṛjā'. The Mahābhāṣya says: 'rā yi is Vedic' (here there is a variant reading: 'rā yiḥ is Vedic'). And under the rule 'vānto yi' (Pāṇini 6.1.79), Kaiyaṭa [says] that this refers to the Vedic character of the word rai ending in [the affix] kyac, but not of the bare [word rai] as well. He himself states another view, that the bare [word] is also Vedic. .. Thus end the stems ending in ai ..