CC Madhya 11.209
madhye madhye ‘hari’ kahe ānandita hañā
They ate all kinds of cakes and sweet rice, filling themselves up to their throats, and at intervals they vibrated the holy name of the Lord in great jubilation.
It is the practice of Vaiṣṇavas while taking prasādam to chant the holy name of Lord Hari at intervals and also sing various songs, such as śarīra avidyā-jāla. Those who are honoring prasādam, accepting the remnants of food offered to the Deity, must always remember that prasādam is not ordinary food. Prasādam is transcendental. We are therefore reminded:
sv-alpa-puṇya-vatāṁ rājan viśvāso naiva jāyate
Those who are not pious cannot understand the value of mahā- prasādam or the holy name of the Lord. Both prasādam and the Lord’s name are on the Brahman platform, or spiritual platform. One should never consider prasādam to be like ordinary hotel cooking. Nor should one touch any kind of food not offered to the Deity. Every Vaiṣṇava strictly follows this principle and does not accept any food that is not prasādam. One should take prasādam with great faith and should chant the holy name of the Lord and worship the Deity in the temple, always remembering that the Deity, mahā-prasādam and the holy name do not belong to the mundane platform. By worshiping the Deity, eating prasādam and chanting the Hare Kṛṣṇa mahā-mantra, one can always remain on the spiritual platform (brahma-bhūyāya kalpate).