Caitanya-caritāmṛta 16.61
ei tina-sevā haite kṛṣṇa-premā haya punaḥ punaḥ sarva-śāstre phukāriyā kaya
[ei tina-sevaa haite krishna-premaa haya punah punah sarva-shaastre phukaariyaa kaya]
Blended reading (Sanskrit + English inline)
ei tina-sevā haite kṛṣṇa-premā haya punaḥ punaḥ sarva-śāstre phukāriyā kaya
By rendering service to these three, one attains the supreme goal of ecstatic love for Kṛṣṇa. In all the revealed scriptures this is loudly declared again and again.
My note
Source: vedabase.io