CC Ādi 14.17

ei ta’ karibe vaiṣṇava-dharmera pracāra
ihā haite habe dui kulera nistāra
Word for word: 
ei ta’ — this child; karibe — will do; vaiṣṇava — of Vaiṣṇavism, or devotional service; dharmera — of the religion; pracāra — preaching; ihā haite — from this; habe — there will be; dui — two; kulera — dynasties; nistāra — deliverance.
Translation: 
“This child will preach the Vaiṣṇava cult and deliver both His maternal and paternal families.
Purport: 

Only Nārāyaṇa Himself or His bona fide representative can preach the cult of Vaiṣṇavism, or devotional service. When a Vaiṣṇava is born, he delivers both his maternal and paternal families simultaneously.