The speech of the celestial angels abounds in the vowels A (ah, as in father), and U (as u in rule). One may often determine from the Hebrew vowels in a passage which words belong to the class of celestials and which to the spirituals — i.e., whether they involve good or truth. The former use more frequently the sounds of O and U, for they have a full tone, and also occur oftener in the Third Heaven. (Heaven and Hell 241; True Christian Religion 278;, Spiritual Experiences 5112, 5620, 5787)

5621. From this is evident that the Word is Divine in its details not only as to the words but also as to the characters or letters. And from this is known what is meant [by the statement] that not the least point or least little horn should perish [Matt 5:18, Luke 16:17], why the Jews had been moved to number the individual letters, and that they have believed there are mysteries in the individual letters as well, although they have not known how.