Śrīmad-Bhāgavatam · Text 5.4.7
Who is speaking and story frame
ब्रह्मण्योऽन्य: कुतो नाभेर्विप्रा मङ्गलपूजिता: ।
यस्य बर्हिषि यज्ञेशं दर्शयामासुरोजसा ॥ ७ ॥
brahmaṇyo ’nyaḥ kuto nābher
viprā maṅgala-pūjitāḥ
yasya barhiṣi yajñeśaṁ
darśayām āsur ojasā
[The second prayer is this.] “Who is a better worshiper of brāhmaṇas than Mahārāja Nābhi? Because he worshiped the qualified brāhmaṇas to their full satisfaction, the brāhmaṇas, by their brahminical prowess, showed Mahārāja Nābhi the Supreme Personality of Godhead, Nārāyaṇa, in person.”
Read Śrīla Prabhupāda's purport on Vedabase.io