The Vadera family are feeding us through the ears and mouth. Your mind is being satisfied through the Katha and your body through food. In addition, this is satisfying the ancestors. This is true tarpan (meaning, to satisfy). In satisfying the ancestors, we mainly use water in our rituals.
In a Yagya, there is mainly the use of fire. Through the fire in a Yagya, you are feeding the demi-gods. Thus, when you perform a fire sacrifice, the oblation offered must be done with the emotion of feeding the demi-gods. The oblation must be offered on the utterance of the word svāhā, with the posture of the hand being in mrugi mudrā (that of a deer). In addition, one must be alert that the oblation does not fall outside the Yagya pit. Take Yagya seriously like a major surgery.