Srimad Bhagavatam — Dvadasha Skandha, Shloka 4
Bhāgavatam Mahimā — The Glory, Measure, Transmission, and Gift of Śrīmad-Bhāgavatam
ब्राह्मं दशसहस्राणि पाद्मं पञ्चोनषष्टि च । श्रीवैष्णवं त्रयोविंशच्चतुर्विंशति शैवकम् ॥ ४ ॥ दशाष्टौ श्रीभागवतं नारदं पञ्चविंशति । मार्कण्डं नव वाह्नं च दशपञ्च चतु:शतम् ॥ ५ ॥ चतुर्दश भविष्यं स्यात्तथा पञ्चशतानि च । दशाष्टौ ब्रह्मवैवर्तं लैङ्गमेकादशैव तु ॥ ६ ॥ चतुर्विंशति वाराहमेकाशीतिसहस्रकम् । स्कान्दं शतं तथा चैकं वामनं दश कीर्तितम् ॥ ७ ॥ कौर्मं सप्तदशाख्यातं मात्स्यं तत्तु चतुर्दश । एकोनविंशत्सौपर्णं ब्रह्माण्डं द्वादशैव तु ॥ ८ ॥ एवं पुराणसन्दोहश्चतुर्लक्ष उदाहृत: । तत्राष्टदशसाहस्रं श्रीभागवतमिष्यते ॥ ९ ॥
brāhmaṁ daśa sahasrāṇi pādmaṁ pañcona-ṣaṣṭi ca śrī-vaiṣṇavaṁ trayo-viṁśac catur-viṁśati śaivakam
The Brahma Purāṇa has ten thousand verses, the Padma Purāṇa fifty-five thousand; the Śrī Viṣṇu Purāṇa twenty-three thousand, the Śiva Purāṇa twenty-four thousand; and Śrīmad-Bhāgavatam eighteen thousand. The Nārada Purāṇa has twenty-five thousand, the Mārkaṇḍeya Purāṇa nine thousand, the Agni (Vāhni) Purāṇa fifteen thousand four hundred; the Bhaviṣya Purāṇa fourteen thousand five hundred, the Brahma-vaivarta Purāṇa eighteen thousand, and the Liṅga Purāṇa eleven thousand. The Varāha Purāṇa contains twenty-four thousand, the Skanda Purāṇa eighty-one thousand one hundred, the Vāmana Purāṇa ten thousand; the Kūrma Purāṇa seventeen thousand, the Matsya Purāṇa fourteen thousand, the Garuḍa (Sauparṇa) Purāṇa nineteen thousand, and the Brahmāṇḍa Purāṇa twelve thousand verses. Thus the total of all Purāṇas is four hundred thousand verses; of these, eighteen thousand belong to the glorious Bhāgavatam.
Śrīla Jīva Gosvāmī has quoted from the Matsya Purāṇa as follows: