Summary: Remembering the night that angels announced the birth of the Saviour.
“In the same region there were shepherds out in the field, keeping watch over their flock by night. And an angel of the Lord appeared to them, and the glory of the Lord shone around them, and they were filled with great fear. And the angel said to them, ‘Fear not, for behold, I bring you good news of great joy that will be for all the people. For unto you is born this day in the city of David a Savior, who is Christ the Lord. And this will be a sign for you: you will find a baby wrapped in swaddling cloths and lying in a manger.’ And suddenly there was with the angel a multitude of the heavenly host praising God and saying,
‘Glory to God in the highest,
and on earth peace among those with whom he is pleased!’
“When the angels went away from them into heaven, the shepherds said to one another, ‘Let us go over to Bethlehem and see this thing that has happened, which the Lord has made known to us.’ And they went with haste and found Mary and Joseph, and the baby lying in a manger. And when they saw it, they made known the saying that had been told them concerning this child. And all who heard it wondered at what the shepherds told them. But Mary treasured up all these things, pondering them in her heart. And the shepherds returned, glorifying and praising God for all they had heard and seen, as it had been told them.’” 
The shepherds had already turned in for the night. Assigned responsibility to guard the flocks destined for Temple worship, one shepherd remained on watch standing on the watchtower, the Migdal Eder, the tower situated close to Bethlehem, on the road to Jerusalem. These were not ordinary shepherds; each man was a priest qualified for Temple worship. The flocks the shepherds were guarding were destined for sacrifice in the Temple. The flocks were pastured near Bethlehem year round and these particular shepherds watched the Temple-flocks throughout the year. 
One dramatic night, the flocks resting under their watchful eyes were soon to be brought to Jerusalem for sacrifice during the Pascal observance. Almost all of the sheep resting before them would soon be sacrificed and slaughtered. Little did they know that another lamb was about to be born. This lamb, also, was destined for sacrifice.
These shepherds should not have been surprised at what was about to take place; after all, they were well-versed in the Talmudic writings. They had been trained in the ancient writings. They knew that Messiah would be born in Bethlehem. Not only had Micah spoken of that birth,  but various Targums were united in pointing to Bethlehem as the place where Messiah would be born. Moreover, it was from the Migdal Eder, the sacred watchtower from which Temple flocks were guarded that His birth would be announced.  However, much like modern worshippers, we grow familiar with the sacred writings and manage to shove their meaning far from us.
One shepherd was awake; he was posted to watch for predators and to ensure that the sheep didn’t become restless and wander off during the night. The other shepherds were in various stages of sleep. All alike were jolted awake by the brilliance of a light that shone from the heavens. Bathed in light so white that it is indescribable, they squinted or shielded their eyes with their hands as they looked up in terror. What could cause such blinding brightness?