Matsyapurana 53.72

53.72

āhṛtya nāradāyaivaṃ tena vālmīkaye punaḥ
vālmīkinā ca lokeṣu dharmakāmārthasādhanam
evaṃ sapādāḥ pañcaite lakṣā martye prakīrtitāḥ //

Brahmâ narrated the original Râmâyaṇa to Nârada; the latter revealed it to Vâlmîki, who gave it to the world, and which is a means of giving Dharma, Kâma and Artha. And in which way the famous epic exists in the world, and contains 5,25,000 ślokas.—71.