SB 10.74.50

varṇitaṁ tad upākhyānaṁ
 mayā te bahu-vistaram
vaikuṇṭha-vāsinor janma
 vipra-śāpāt punaḥ punaḥ
Word for word: 
varṇitam — related; tat — that; upākhyānam — account; mayā — by me; te — to you; bahu — much; vistaram — in detail; vaikuṇṭha-vāsinoḥ — of the two residents of the eternal kingdom of God (namely, the doorkeepers Jaya and Vijaya); janma — the material birth; vipra — of brāhmaṇas (the four Kumāras); śāpāt — due to the curse; punaḥ punaḥ — again and again.
Translation: 
I have already described to you in detail the history of the two residents of Vaikuṇṭha who had to undergo repeated births in the material world because of being cursed by brāhmaṇas.