God is an unutterable sigh, planted in the depths of the soul. Jean Paul
The unutterable violence of the Holocaust shook our confidence in the possibility of telling any story of faith at all. Timothy Radcliffe
Words are made for a certain exactness of thought, as tears are for a certain degree of pain. What is least distinct cannot be named; what is clearest is unutterable. Rene Daumal
Therefore the elect shall go forth... to see the torments of the impious, seeing which they will not be grieved, but will be satiated with joy at the sight of the unutterable calamity of the impious. Peter Lombard