The affix ṇa is also used after the verbs - śyai 'to go', verbs ending in a long bhā , vyad 'to pierce', āsru 'to pain', saṃtru 'to flow', atīṇ 'to pass on', avasā 'to complete', avaha 'to take away', liha 'to lick', śliṣa 'to embrace' and śvasa 'to breathe'.,
The root श्यै, before affixes, becomes श्या, (VI. I. 45) and is thus included in the phrase 'verbs ending in long आ'. What is then the use of its separate enumeration? The separate enumeration is for the sake of excluding the application of every other rule which might have prohibited ण. Thus (III. I. 136) enjoins क when a compound verb ends in अ. But that rule does not apply to the verb श्या.
Thus अवश्यायः 'frost', प्रतिश्यायः 'catarrh', दायः 'inheritance', धायः 'having', व्याधः 'pain', आस्रावः 'wound', संस्रावः 'flow', अत्यायः 'transgression', अवसायः 'conclusion', अवहारः 'taken away', लेहः 'licking', श्लेषः 'embracing', श्वासः 'breath'. See 7.3.33.,