"VI.10. And he will see his face with jubilation. We heard above how God influences us by becoming known to us, but now we are told how he cheers us up while making himself known to us. When we suffer compunction we look inward, and we are seized with fear because of the evil we have done: that is one way. The other way is that when looking heavenward with joy we are confirmed by a kind of hope and security. The former compunction influences us and saddens us, the latter moves us to tears of joy. We us the word jubilation when an unspeakable joy takes hold of the mind, joy that can neither be hidden nor be aroused by words. Nevertheless it is produced by certain emotions, although it expresses no discernible meaning.
So the prophet David, knowing that the souls of the elect conceive joy in their minds, a joy that they cannot express in words, said, Blessed are the people who know the joyful shout. He did not say "who speaks," but who know, because jubilation can certainly be known intellectually, but it cannot be expressed in words. That which is above the senses is nevertheless sensed by jubilation. When the consciousness of the one who senses is hardly capable of contemplating what is above the senses, how could the tongue of a speaker manage to express it? When accordingly the light of truth inserts itself into our hearts, sometimes it delights us by opening up interior joys, so that after bitter temptations and after sad trials, Elihu rightly adds, And he will see his face with jubilation. Gregory the Great pg. 74 'Moral Reflections on the Book of Job' by Gregory the Great Volume 5 Books 23-27.