Application to Israel: Yahweh points out the tremendous irony that his chosen people have received favors and prophecies but have not understood them. They have had the witness of Yahweh’s power but have not recognized it. Yahweh has shown them “hidden things” but Israel has not recognized them.
Application to Nephi’s audience: Laman and Lemuel were under this same condemnation. Although they had received an angel’s visitation, they still would not “declare” the things of God. Rather they continually rationalized their position and relapsed into old ways.