CC Madhya 1.29

‘caitanya’ seva, ‘caitanya’ gāo, lao ‘caitanya’-nāma
‘caitanye’ ye bhakti kare, sei mora prāṇa
Synonyms: 
caitanya seva — serve Śrī Caitanya Mahāprabhu; caitanya gāo — chant about Śrī Caitanya Mahāprabhu; lao — always take; caitanya-nāma — the name of Lord Caitanya Mahāprabhu; caitanye — unto Lord Śrī Caitanya Mahāprabhu; ye — anyone who; bhakti — devotional service; kare — renders; sei — that person; mora — My; prāṇa — life and soul.
Translation: 
Nityānanda Prabhu requested everyone to serve Śrī Caitanya Mahāprabhu, chant His glories and utter His name. Nityānanda Prabhu claimed that person to be His life and soul who rendered devotional service unto Śrī Caitanya Mahāprabhu.