In Latter-day doctrine, we speak of a symbolic veil that has two applications. In one case, the veil is a mechanism that shades the memory as we transition to Earth from our pre-Earth life. In a second, but related, application, the veil provides a protective barrier to protect us from unauthorized interaction with the Lord in the present. In each instance, the veil is penetrable under circumstances such as the brother of Jared’s great faith that allowed him to see beyond it.
In Ether 3:6, Moroni commented that the veil was taken from the eyes of the brother of Jared, and he saw the finger of the Lord. In Ether 3:19 he says, “Because of the knowledge of this man, he could not be kept from within the veil.” Clearly, the veil is a symbol for the sacred cloud, a holy protection that shields people on the Earth from interacting with the Lord inappropriately.
Book of Mormon Central “Why Did Moroni Use Temple Imagery While Telling the Brother of Jared Story? (Ether 3:20),” KnoWhy 237 (November 23, 2016).