Srimad Bhagavatam Canto 10, Chapter 23, Text 08

SB 10.23.8

diksayah pasu-samsthayah
 sautramanyas ca sattamah
anyatra diksitasyapi
 nannam asnan hi dusyati
 
Translation: 
 
Except during the interval between the initiation of the performer of a sacrifice and the actual sacrifice of the animal, O most pure brahmanas, it is not contaminating for even the initiated to partake of food, at least in sacrifices other than the Sautramani.
 
Purport: 
 
The cowherd boys anticipated the possible objection from the brahmanas that they couldn’t give the boys any food because they themselves had not yet eaten, and that a priest initiated to perform a sacrifice should not eat. Therefore the boys humbly informed the brahmanas about various technicalities of ritualistic sacrifice. The cowherd boys were not unaware of the formalities of Vedic culture, but their real intention was simply to render loving service to Lord Krsna.
Srimad Bhagavatam Canto 10, Chapter 23, Text 07
Srimad Bhagavatam Canto 10, Chapter 23, Text 09