Drona and Dhara, His (Krsna's) eternal father and mother, appeared on earth before Krsna as Nanda Maharaja and Yasoda

Expressions researched:
"Drona and Dhara, His eternal father and mother, appeared on earth before Krsna as Nanda Maharaja and Yasoda"

SB Canto 10.1 to 10.13

Because whenever Kṛṣṇa appears on this earth He superficially needs a father and mother, Droṇa and Dharā, His eternal father and mother, appeared on earth before Kṛṣṇa as Nanda Mahārāja and Yaśodā.

SB 10.8.50, Translation and Purport:

When Brahmā said, "Yes, let it be so," the most fortunate Droṇa, who was equal to Bhagavān, appeared in Vrajapura, Vṛndāvana, as the most famous Nanda Mahārāja, and his wife, Dharā, appeared as Mother Yaśodā.

Because whenever Kṛṣṇa appears on this earth He superficially needs a father and mother, Droṇa and Dharā, His eternal father and mother, appeared on earth before Kṛṣṇa as Nanda Mahārāja and Yaśodā. In contrast to Sutapā and Pṛśni, they did not undergo severe penances and austerities to become the father and mother of Kṛṣṇa. This is the difference between nitya-siddha and sādhana-siddha.