The definition of a whisper is to speak with soft, hushed sounds, using the breath but with no vibration of vocal cords.
In order to hear a whisper, one must be in close proximity of the speaker to hear.
So close, that you might even feel the breath of the one you are listening to.
The same is true with God. We must always be in close proximity to hear from him. That also means being so close, that we can literally feel "the breath of God."
As a child lovingly whispers in the ear of her elder, so God lovingly whispers in the ear of his children.
The Whisper of a Loving Father.