Yāska's Nirukta 6.31

6.31

``vāmaṃvāmam ta ādure devo dadātv aryamā/
vāmam pūṣā vāmam bhago vāmam devaḥ karūḷatī/(ṛV.4,30,24)''
vāmam vananīyam bhavaty ādurir ādaraṇāt/
tat kaḥ karūḷatī/
bhagaḥ purastāt tasyānvādeśa ity ekam pūṣā ity aparam sodantakah/
``adantakaḥ pūṣā''
iti ca brāhmaṇam/
``dano viśa indra mṛdhravācah/''
dānamanaso no manuṣyān indra mṛduvācaḥ kuru/
``avīrām iva mām ayam śarārur abhi manyate/''
abalām iva mām ayam bālo abhimanyate saṃśiśariṣuh/
idamyur idam kāmayamāṇah/
athāpi tadvad arthe bhāṣyate/
``vasūyur indro''
vasumān ity atra arthah/
``aśvayurgavyū rathayur vasūyur indra''
ity api nigamo bhavati/