The phrase "in that day" is a Hebraism for on that day (compare Exodus 10:28, "And Pharaoh said unto him, Get thee from me, take heed to thyself, see my face no more; for in that day thou seest my face thou shalt die"). [Zarahemla Research Foundation, Study Book of Mormon, p. 7]
Through the Wilderness to the Promised Land
(1 Nephi )