Lord Krsna and Balarama are not two different Personalities of Godhead. God is one without a second, but He expands Himself in many forms without their being separate from one another. They are all plenary expansions

Expressions researched:
"Lord Kṛṣṇa and Balarāma are not two different Personalities of Godhead. God is one without a second, but He expands Himself in many forms without their being separate from one another. They are all plenary expansions"

SB Canto 3

Lord Kṛṣṇa and Balarāma are not two different Personalities of Godhead. God is one without a second, but He expands Himself in many forms without their being separate from one another. They are all plenary expansions.

SB 3.1.26, Translation and Purport:

(Please tell me) whether the original Personalities of Godhead, who incarnated Themselves at the request of Brahmā (who is born out of the lotus flower from the Lord) and who have increased the prosperity of the world by elevating everyone, are doing well in the house of Śūrasena.

Lord Kṛṣṇa and Balarāma are not two different Personalities of Godhead. God is one without a second, but He expands Himself in many forms without their being separate from one another. They are all plenary expansions. The immediate expansion of Lord Kṛṣṇa is Baladeva, and Brahmā, born from the lotus flower from Garbhodakaśāyī Viṣṇu, is an expansion of Baladeva. This indicates that Kṛṣṇa and Baladeva are not subjected to the regulations of the universe; on the contrary, the whole universe is under Their subjugation. They appeared at the request of Brahmā to liberate the burden of the world, and They relieved the world by many superhuman activities so that everyone became happy and prosperous. Without the grace of the Lord, no one can become happy and prosperous. Because the happiness of the family of the Lord's devotees depends on the happiness of the Lord, Vidura first of all inquired about the well-being of the Lord.