SB 10.84.39

ṛṇais tribhir dvijo jāto
 devarṣi-pitṝṇāṁ prabho
yajñādhyayana-putrais tāny
 anistīrya tyajan patet
Synonyms: 
ṛṇaiḥ — with debts; tribhiḥ — three; dvi-jaḥ — a member of the twice-born classes; jātaḥ — is born; deva — to the demigods; ṛṣi — sages; pitṝṇām — and forefathers; prabho — O master (Vasudeva); yajña — by sacrifice; adhyayana — study of scripture; putraiḥ — and (begetting) children; tāni — these (debts); anistīrya — not liquidating; tyajan — leaving (his body); patet — he falls down.
Translation: 
Dear Prabhu, a member of the twice-born classes is born with three kinds of debts — those owed to the demigods, to the sages and to his forefathers. If he leaves his body without first liquidating these debts by performing sacrifice, studying the scriptures and begetting children, he will fall down into a hellish condition.
Purport: 

Concerning the special obligations of a brāhmaṇa, the śruti states, jāyamāno vai brāhmaṇas tribhir ṛṇavāñ jāyate brahmacaryeṇa ṛṣibhyo yajñena devebhyaḥ prajayā pitṛbhyaḥ: “Whenever a brāhmaṇa takes birth, three debts are born along with him. He can pay his debt to the sages by celibacy, his debt to the demigods by sacrifice, and his debt to his forefathers by begetting children.”