kopaṃ yatnena dhārayan
sva-putraṃ nāradaṃ prāha
aśravya—what should not be heard; śravaṇāt—from hearing; jātam—generated; kopam—anger; yatnena— with some effort; dhārayan—checking; sva-putram— to his son; nāradam—Nārada; prāha—he said; sa-ākṣepam—with rebuke; catuḥ-ānanaḥ—four-headed Brahmā.
56. With some effort, the four-headed Brahmā checked the anger stirred within him by hearing what no one should hear and rebuked his son Nārada.
Having to work with the material mode of passion, Lord Brahmā is sometimes briefly affected by anger. Here, because his son praised him inaptly as the independent Supreme Lord, he almost lost his temper.