Devibhagavatapurana 1.3.18

1.3.18

manvantareṣu sarveṣu dvāpare dvāpare yuge |
prāduḥkaroti dharmārthī purāṇāni yathāvidhi ||

At every Manvantara, in each Dvâpara Yuga, Veda Vyâsa expounds the Purânas duly to preserve the religion. Veda Vyâsa is no other person than Visnu Himself; He, in the form of Veda Vyâsa, divides the (one) Veda into four parts, in every Dvâpara Yuga, for the good of the world. The Brahmânas of the Kali age are shortlived and their intellect (Buddhi) is not sharp; they cannot realise the meaning after studying the Vedas; knowing this in every Dvâpara Yuga Bhagavân expounds the holy Purâna Samhitas. The more so because women, S’udras, and the lower Dvijas are not entitled to hear the Vedas; for their good, the Purânas have been composed. Tne present auspicious Manvantara is Vaivasvata; it is the seventh in due order; and the son of Satyavati, the best of the knowers of Dharma, is the Veda Vyâsa of the 28th Dvâpara Yuga of this seventh Manvantara. He is my Guru; in the next Dvâpara, Yuga Asvatthama, the son of Drona will be the Veda Vyâsa. Twenty-seven Veda Vyâsas had expired and they duly compiled each their own Purâna Samhitas in their own Dvâpara Yugas.