The mathematics of this episode indicate that “until they had all gone forth,” is either hyperbole or we are dealing with a longer period of time than a single day. If each person were to spend a minute with the Lord, only 720 people could come to the Lord in 12 hours of daylight. Obviously cutting the amount of time spent would decrease the amount of time required, but when we consider that in addition to this event we have various sermons and have no indication of the ending of a session with the Lord until the end of our chapter 18, then we appear to have more events than will fit into a day.
It is most probable that the problem is not simply one of the timing of the personal contact with the Savior, but of all of the events listed for the “first day.” The nature of the discourses presented suggests that Nephi is again crafting his account, and the “first day” is more symbolic than literal. The Messiah may have spent more time with the Nephites prior to the ascension indicated in 3 Nephi 18:39.
The other possibility is that the “until they had all gone forth,” indicated something less than all who were present, and this event took much less time that it could have. Nevertheless, we still have the various sermons to fit into a day. Given that Nephi has already shown that he is willing to create an account that deals with different spaces and times when he recorded the events of destruction, we should be willing to allow him the leeway to have given us a generalized accounting rather than a specific one. We must remember that for Nephi the message was much more important than the technical timing of the delivery of the message.