Revākhaṇḍa ascribed to the Vāyupurāṇa (RKV) 168.24

168.24

yadi tuṣṭo mahādeva varado 'si sureśvara /
durlabhaṃ sarvabhūtānāmamaratvaṃ prayaccha me //

"If you are pleased, O Mahādeva, and are a granter of boons, O lord of the gods,
grant me immortality, which is difficult for all beings to obtain;