SB 8.16.47

evaṁ tv ahar ahaḥ kuryād
 dvādaśāhaṁ payo-vratam
harer ārādhanaṁ homam
 arhaṇaṁ dvija-tarpaṇam
Word for word: 
evam — in this way; tu — indeed; ahaḥ ahaḥ — day after day; kuryāt — should execute; dvādaśa-aham — until twelve days; payaḥ-vratam — the observance of the vrata known as payo-vrata; hareḥ ārādhanam — worshiping the Supreme Personality of Godhead; homam — by executing a fire sacrifice; arhaṇam — worshiping the Deity; dvija-tarpaṇam — and satisfying the brāhmaṇas by feeding them.
Translation: 
In this way, until twelve days have passed, one should observe this payo-vrata, worshiping the Lord every day, executing the routine duties, performing sacrifices and feeding the brāhmaṇas.