The act of love plunges us into God, who is given in silence. Anything else would run the risk of detracting from the gift. "Silence is the speech of God", according to St. John of the Cross. This act of love frees us from ourselves. In this love, God is revealed in a silence that strips us and makes us experience that "blessed are the poor". Silence preserves us from illusion and gives us security ... The grace of contemplation places the soul in a kind of immobility and silence, which we cannot do of ourselves. God does all this by way of love, which involves a death of the mind and a resurrection of the heart.
If the heart wanders or is distracted, bring it back to the point quite gently -- and even if you do nothing during the whole of your prayer but bring your heart back, though it went away every time you brought it back, your time would be very well employed.