Skandapurana 6.3.186.6

6.3.186.6

śrīmaheśa uvāca -
durlabhaḥ prāṇināṃ tāta yo varaḥ prārthito'nagha .
devadevasya vāhanaṃ dvijendratvaṃ sudurlabham .. 186.6 ..

Śrī Maheśa said:
"Difficult for living beings to attain, dear child, is the boon you have requested, O sinless one: / to be the mount of the God of gods, and kingship over birds, is exceedingly hard to attain.