Caitanya-caritāmṛta 4.103
avatārera āra eka āche mukhya-bīja rasika-śekhara kṛṣṇera sei kārya nija
[avataarera aara eka aache mukhya-beeja rasika-shekhara krishnera sei kaarya nija]
Blended reading (Sanskrit + English inline)
avatārera āra eka āche mukhya-bīja rasika-śekhara kṛṣṇera sei kārya nija
There is a principal cause for Lord Kṛṣṇa’s appearance. It grows from His own engagements as the foremost enjoyer of loving exchanges.
My note
Source: vedabase.io