Manava Dharmashastra 3.236

3.236

atyuṣṇaṃ sarvam annaṃ syād bhuñjīraṃs te ca vāgyatāḥ
na ca dvijātayo brūyur dātrā pṛṣṭā havirguṇān //

All the food must be very hot, and the (guests) shall eat in silence; (even though) asked by the giver (of the feast), the Brahmanas shall not proclaim the qualities of the sacrificial food.