Daily Reading: Srimad Bhagavatam page-69

SB 1.3.25

athāsau yuga-sandhyāyāṁ
 dasyu-prāyeṣu rājasu
janitā viṣṇu-yaśaso
 nāmnā kalkir jagat-patiḥ

Translation: 

Thereafter, at the conjunction of two yugas, the Lord of the creation will take His birth as the Kalki incarnation and become the son of Viṣṇu Yaśā. At this time almost all the rulers of the earth will have degenerated into plunderers.

Purport: 

Here is another foretelling of the advent of Lord Kalki, the incarnation of Godhead. He is to appear at the conjunction of the two yugas, namely at the end of Kali-yuga and the beginning of Satya-yuga. The cycle of the four yugas, namely Satya, Tretā, Dvāpara and Kali, rotates like the calendar months. The present Kali-yuga lasts 432,000 years, out of which we have passed only 5,000 years after the Battle of Kurukṣetra and the end of the regime of King Parīkṣit. So there are 427,000 years balance yet to be finished. Therefore at the end of this period, the incarnation of Kalki will take place, as foretold in the Śrīmad-Bhāgavatam. The name of His father, Viṣṇu Yaśā, a learned brāhmaṇa, and the village Śambhala are also mentioned. As above mentioned, all these foretellings will prove to be factual in chronological order. That is the authority of Śrīmad-Bhāgavatam.

SB 1.3.26

avatārā hy asaṅkhyeyā
 hareḥ sattva-nidher dvijāḥ
yathāvidāsinaḥ kulyāḥ
 sarasaḥ syuḥ sahasraśaḥ

Translation: 

O brāhmaṇas, the incarnations of the Lord are innumerable, like rivulets flowing from inexhaustible sources of water.

Purport: 

The list of incarnations of the Personality of Godhead given herein is not complete. It is only a partial view of all the incarnations. There are many others, such as Śrī Hayagrīva, Hari, Haṁsa, Pṛśnigarbha, Vibhu, Satyasena, Vaikuṇṭha, Sārvabhauma, Viṣvaksena, Dharmasetu, Sudhāmā, Yogeśvara, Bṛhadbhānu and others of the bygone ages. Śrī Prahlāda Mahārāja said in his prayer, “My Lord, You manifest as many incarnations as there are species of life, namely the aquatics, the vegetables, the reptiles, the birds, the beasts, the men, the demigods, etc., just for the maintenance of the faithful and the annihilation of the unfaithful. You advent Yourself in this way in accordance with the necessity of the different yugas. In the Kali-yuga You have incarnated garbed as a devotee.” This incarnation of the Lord in the Kali-yuga is Lord Caitanya Mahāprabhu. There are many other places, both in the Bhāgavatam and in other scriptures, in which the incarnation of the Lord as Śrī Caitanya Mahāprabhu is explicitly mentioned. In the Brahma-saṁhitā also it is said indirectly that although there are many incarnations of the Lord, such as Rāma, Nṛsiṁha, Varāha, Matsya, Kūrma and many others, the Lord Himself sometimes incarnates in person. Lord Kṛṣṇa and Lord Śrī Caitanya Mahāprabhu are not, therefore, incarnations, but the original source of all other incarnations. This will be clearly explained in the next śloka. So the Lord is the inexhaustible source for innumerable incarnations which are not always mentioned. But such incarnations are distinguished by specific extraordinary feats which are impossible to be performed by any living being. That is the general test to identify an incarnation of the Lord, directly and indirectly empowered. Some incarnations mentioned above are almost plenary portions. For instance, the Kumāras are empowered with transcendental knowledge. Śrī Nārada is empowered with devotional service. Mahārāja Pṛthu is an empowered incarnation with executive function. The Matsya incarnation is directly a plenary portion. So the innumerable incarnations of the Lord are manifested all over the universes constantly, without cessation, as water flows constantly from waterfalls.