Yāska's Nirukta 5.15

5.15

``sa it tamo avayunam tatanvat sūryeṇa vayunavac cakāra/
sa tamo aprajñānam tatanvat sa tam sūryeṇa prajñānavac cakāra/(ṛV.6,21,3)''
vāja pastyam vāja patanam/
``sanema vāja pastyam.(ṛV.9,98,12)''
ity api nigamo bhavati/
vāja gandhyam gadhyaty uttarapadam/
``aśyāma vāja gandham.(ṛV.9,98,12)''
ity api nigamo bhavati/
gadhyam gṛhṇāteh/
``ṛjrā vājam na gadhyam yuyūṃṣan.(ṛV.4,16,11)''
ity api nigamo bhavati/
gadhyatir miśrībhāva karmā/
``āgadhitā parigadhitā.(ṛV.1,126,6)''
ity api nigamo bhavati/
kaurayāṇaḥ kṛtayānah/
``pākasthāmā kaurayāṇaḥ.(ṛV.8,3,21)''
ity api nigamo bhavati/
taurayāṇas tūrṇayānah/
``sa taurayāṇa upa yāhi yajñam marudbhir indra sakhibhiḥ sajoṣāh/''
ity api nigamo bhavati/
ahrayāṇo ahrītayānah/
``anuṣṭuyā kṛṇuhy ahrayāṇaḥ.(ṛV.4,4,14)''
ity api nigamo bhavati/
harayāṇo haramāṇayānah/
``rajatam harayāṇaḥ.(ṛV.8,25,22)''
ity api nigamo bhavati/
``ya āritaḥ karmaṇikarmaṇi sthirah/''
pratyṛtaḥ stomān/
vrandī vrandater mṛdūbhāva karmaṇah/