देवा ह वै प्रजापतिमब्रुवन्नानुष्टुभस्य मन्त्रराजस्य फलं नो ब्रूहि भगव इति स होवाच प्रजापतिर्य एतं मन्त्रराजं
In plain words
The gods once came to Prajāpati and asked him outright: 'Tell us what this king of mantras, the anuṣṭubh, actually gives.' And Prajāpati began his answer: 'Whoever takes up this king of mantras —'
Close to the Sanskrit
The gods indeed said to Prajāpati: 'Tell us the fruit of the king of mantras, the anuṣṭubh, O venerable one.' He, Prajāpati, said: 'Whoever [recites] this king of mantras —'