2133. Two or three times, by the Lord's divine mercy, heaven has opened so wide to me that I have heard the whole of it praising the Lord's glory. The process involves many communities praising him all together, with one heart, while at the same time each individual community participates by itself, with its own distinctive feelings and so its own thoughts. A heavenly sound could be heard far and wide, a sound so vast that my ears failed to reach its outer bounds, as the eye does when it observes the universe. The experience brought the deepest possible joy and happiness.
At times I also perceived heaven's praise of the Lord's glory as resembling a ray of light streaming down and touching the inner reaches of the mind.
Angels praise the Lord this way when they feel calm and peaceful, because then their praise flows from their very deepest joys and true happiness.