3 Nephi 1 :12-22
And it came to pass that he cried mightily unto the Lord all that day; and behold, the voice of the Lord came unto him, saying:
13 Lift up your head and be of good cheer; for behold, the time is at hand, and on this night shall the sign be given, and on the morrow come I into the world, to show unto the world that I will fulfil all that which I have caused to be spoken by the mouth of my holy prophets.
14 Behold, I come unto my own, to fulfil all things which I have made known unto the children of men from the foundation of the world, and to do the will, both of the Father and of the Son—of the Father because of me, and of the Son because of my flesh. And behold, the time is at hand, and this night shall the sign be given.
15 And it came to pass that the words which came unto Nephi were fulfilled, according as they had been spoken; for behold, at the going down of the sun there was no darkness; and the people began to be astonished because there was no darkness when the night came.
16 And there were many, who had not believed the words of the prophets, who fell to the earth and became as if they were dead, for they knew that the great plan of destruction which they had laid for those who believed in the words of the prophets had been frustrated; for the sign which had been given was already at hand.
17 And they began to know that the Son of God must shortly appear; yea, in fine, all the people upon the face of the whole earth from the west to the east, both in the land north and in the land south, were so exceedingly astonished that they fell to the earth.
18 For they knew that the prophets had testified of these things for many years, and that the sign which had been given was already at hand; and they began to fear because of their iniquity and their unbelief.
19 And it came to pass that there was no darkness in all that night, but it was as light as though it was mid-day. And it came to pass that the sun did rise in the morning again, according to its proper order; and they knew that it was the day that the Lord should be born, because of the sign which had been given.
20 And it had come to pass, yea, all things, every whit, according to the words of the prophets.
21 And it came to pass also that a new star did appear, according to the word.
‘Of all the Christmas greetings ever uttered, certainly, this is the greatest. Even though the shepherds in Judea were to see an angel and hear the heavenly hosts singing, Glory to God in the highest, and on earth peace, good will toward men (Lu 2:14), Nephi received notice from the Lord himself in a most personal and intimate communication. This message of peace and good cheer must have soothed Nephi’s soul like nothing else. Certainly, that same message has soothed the souls of millions since.
Indeed, all of creation had looked forward to this moment. From Adam’s early sacrifices in ignorance to the words of Samuel just 5 years prior, 4000 years of prophets and other righteous souls had their entire belief system resting on the promise that the Son of God would be made flesh and dwell among men. All of the Law of Moses had pointed to a Messiah who would redeem the people from their sins. Accordingly, many had received remission of sins even prior to the birth of the Lamb (Enos 1:5-8; Alma 36:18-19). Finally, the prophecies from all the prophets would be vindicated. The faith and hope of millions had to wait as much as four millennia to be realized, but the promised time had finally come.’ (Bryan Richards, gospeldoctrine.com)