To keep her (Kunti's) virginity undisturbed, the sun-god arranged to give her a child that came from her ear, and therefore the child was known as Karna

Expressions researched:
"To keep her virginity undisturbed, the sun-god arranged to give her a child that came from her ear, and therefore the child was known as Karṇa"

Srimad-Bhagavatam

SB Canto 9

According to Vedic civilization, if a girl gives birth to a child before she is married, no one will marry her. Therefore although the sun-god, after appearing before Pṛthā, wanted to give her a child, Pṛthā hesitated because she was still unmarried. To keep her virginity undisturbed, the sun-god arranged to give her a child that came from her ear, and therefore the child was known as Karṇa.

SB 9.24.34, Translation and Purport

The sun-god said: O beautiful Pṛthā, your meeting with the demigods cannot be fruitless. Therefore, let me place my seed in your womb so that you may bear a son. I shall arrange to keep your virginity intact, since you are still an unmarried girl.

According to Vedic civilization, if a girl gives birth to a child before she is married, no one will marry her. Therefore although the sun-god, after appearing before Pṛthā, wanted to give her a child, Pṛthā hesitated because she was still unmarried. To keep her virginity undisturbed, the sun-god arranged to give her a child that came from her ear, and therefore the child was known as Karṇa. The custom is that a girl should be married akṣata-yoni, that is, with her virginity undisturbed. A girl should never bear a child before her marriage.