On the Hare Krishna Mantra

This sound vibration is not material, it is spiritual, and powerful beyond our conception. So it cannot be hindered in any way by something material; it surpasses all these material barriers. So you can know it that when you are chanting, you are also giving benefit to even the child in the womb.

 

Srila Prabhupada's Letter to Mukunda and Janaki, Los Angeles, February 28, 1968