"Here the heart opens wide in joy and desire, all the veins dilate, and the powers of the soul stand ready in their desire to fulfill what is called for by God and by the invitation to unity with him. This invitation consists in the shining of Christ, the eternal sun, upon the heart. This causes so much pleasure and joy within the heart and makes the heart open so wide that it can scarcely be closed again.
A person is thereby wounded in his heart from within and feels the wound of love. Being wounded by love is both the sweetest feeling and the sharpest pain that anyone can experience and is a sure sign that he will be healed. This spiritual wound causes pleasure and pain at one and the same time. Christ, the true sun, again casts his light and rays upon the wounded, open heart and invites it once more to unity. This renews the wound and all its pangs.
This interior call and invitation, together with the face that the creature lifts himself up in readiness to offer himself and all that he can do and nevertheless finds himself unable to reach or obtain this unity, causes a spiritual pain. In other words, when the inmost depths of the heart and the very source of life have been wounded by love and when a persons finds himself unable to obtain what he most desires but must ever remain where he does not wish to be, then from this twofold source arises the pain. Here Christ is raised above the topmost part of the mind and casts his divine rays upon the avid desires of the longing heart. This burning radiance dries up and consumes all the moisture, that is, all the powers and forces of human nature. An open and longing heart and the influx of divine rays give rise to an enduring pain." pg. 85,86 John Ruusbroec