Krsna's expansions are compared to candles that have been lit from an original candle

Expressions researched:
"Every candle has the full potential candlepower, but there is still the distinction" |"still the candle from which the others are lit is called the original"

SB Canto 3

With one candle one may light a second candle, with the second a third and then a fourth, and in this way one can light up thousands of candles, and no candle is inferior to another in distributing light. Every candle has the full potential candlepower, but there is still the distinction that one candle is the first, another the second, another the third and another the fourth. Similarly, there is no difference between the immediate expansion of the Lord and His secondary expansion.

SB 3.21.32, Purport:

There are different manifestations of the Lord. He is one, but He has become many. He divides Himself into two different expansions, one called kalā and the other vibhinnāṁśa. Ordinary living entities are called vibhinnāṁśa expansions, and the unlimited expansions of viṣṇu-tattva, such as Vāmana, Govinda, Nārāyaṇa, Pradyumna, Vāsudeva and Ananta, are called svāṁśa-kalā. Svāṁśa refers to a direct expansion, and kalā denotes an expansion from the expansion of the original Lord. Baladeva is an expansion of Kṛṣṇa, and from Baladeva the next expansion is Saṅkarṣaṇa; thus Saṅkarṣaṇa is kalā, but Baladeva is svāṁśa. There is no difference, however, among Them. This is very nicely explained in the Brahma-saṁhitā (5.46): dīpārcir eva hi daśāntaram abhyupetya. With one candle one may light a second candle, with the second a third and then a fourth, and in this way one can light up thousands of candles, and no candle is inferior to another in distributing light. Every candle has the full potential candlepower, but there is still the distinction that one candle is the first, another the second, another the third and another the fourth. Similarly, there is no difference between the immediate expansion of the Lord and His secondary expansion.

There is no difference between the expansion, the expansion of the expansion, and the Supreme Personality of Godhead directly, as there is no difference between one candle and another—but still the candle from which the others are lit is called the original.

SB 3.24.10, Purport:

The word aṁśena also indicates that the Supreme Personality of Godhead, Kṛṣṇa, appeared as Kapiladeva in a portion of His portion. God expands either as kalā or as aṁśa. Aṁśa means "direct expansion," and kalā means "expansion of the expansion." There is no difference between the expansion, the expansion of the expansion, and the Supreme Personality of Godhead directly, as there is no difference between one candle and another—but still the candle from which the others are lit is called the original. Kṛṣṇa, therefore, is called the Parabrahman, or the ultimate Godhead and cause of all causes.

SB Canto 4

In the Vedānta-sūtra, the living entities of different gradations are compared to candles or lamps with different candle power.

SB 4.1.15, Purport:

In the Vedānta-sūtra, the living entities of different gradations are compared to candles or lamps with different candle power. For example, some electric bulbs have the power of one thousand candles, some have the power of five hundred candles, some the power of one hundred candles, some fifty candles, etc., but all electric bulbs have light. Light is present in every bulb, but the gradations of light are different. Similarly, there are gradations of Brahman. The Viṣṇu svāṁśa expansions of the Supreme Lord in different Viṣṇu forms are like lamps, Lord Śiva is also like a lamp, and the supreme candle power, or the one-hundred-percent light, is Kṛṣṇa. The viṣṇu-tattva has ninety-four percent, the śiva-tattva has eighty-four percent, Lord Brahmā has seventy-eight percent, and the living entities are also like Brahmā, but in the conditioned state their power is still more dim. There are gradations of Brahman, and no one can deny this fact.

SB Canto 6

Kṛṣṇa expands Himself as Viṣṇu the way a bright candle kindles another. Although there is no difference between the power of one candle and another, Kṛṣṇa is compared to the original candle.

SB 6.9.45, Purport:

Kṛṣṇa, being the original cause of everything, is the Supreme Person, above even Viṣṇu and Nārāyaṇa, although there is no difference between these different forms of the Lord. As explained in Brahma-saṁhitā (5.46):

dīpārcir eva hi daśāntaram abhyupetya

dīpāyate vivṛta-hetu-samāna-dharmā

yas tādṛg eva hi ca viṣṇutayā vibhāti

govindam ādi-puruṣaṁ tam ahaṁ bhajāmi

Kṛṣṇa expands Himself as Viṣṇu the way a bright candle kindles another. Although there is no difference between the power of one candle and another, Kṛṣṇa is compared to the original candle.

SB Canto 9

SB 9.10.2, Purport:

Lord Rāmacandra and His brothers, Lakṣmaṇa, Bharata and Śatrughna, are all viṣṇu-tattva, not jīva-tattva. The Supreme Personality of Godhead expands into many, many forms. Advaitam acyutam anādim ananta-rūpam (Bs. 5.33). Although they are one and the same, viṣṇu-tattva has many forms and incarnations. As confirmed in the Brahma-saṁhitā (5.39), rāmādi-mūrtiṣu kalā-niyamena tiṣṭhan. The Lord is situated in many forms, such as Rāma, Lakṣmaṇa, Bharata and Śatrughna, and these forms may exist in any part of His creation. All these forms exist permanently, eternally, as individual Personalities of Godhead, and they resemble many candles, all equally powerful. Lord Rāmacandra, Lakṣmaṇa, Bharata and Śatrughna, who, being viṣṇu-tattva, are all equally powerful, became the sons of Mahārāja Daśaratha in response to prayers by the demigods.