Caitanya-caritāmṛta 4.76
avatārī kṛṣṇa yaiche kare avatāra aṁśinī rādhā haite tina gaṇera vistāra
[avataaree krishna yaiche kare avataara amshinee raadhaa haite tina ganera vistaara]
Blended reading (Sanskrit + English inline)
avatārī kṛṣṇa yaiche kare avatāra aṁśinī rādhā haite tina gaṇera vistāra
Just as the fountainhead, Lord Kṛṣṇa, is the cause of all incarnations, so Śrī Rādhā is the cause of all these consorts.
My note
Source: vedabase.io