Revākhaṇḍa ascribed to the Vāyupurāṇa (RKV) 10.44

10.44

kecid dhūmakamaśnanti tapasyugre vyavasthitāḥ /
ātmayajñaratāḥ kecidapare bhaktibhāginaḥ //

some inhaled smoke, established in severe asceticism; / some were devoted to the sacrifice of the self, while others partook of devotion;