Is. 7:14: “Therefore the Lord Himself will give you a sign: Behold, the virgin shall conceive and bear a Son, and shall call His name Immanuel.”
Luke 2:8-14: Now there were in the same country shepherds living out in the fields, keeping watch over their flock by night. And behold, an angel of the Lord stood before them, and the glory of the Lord shone around them, and they were greatly afraid.
Then the angel said to them, “Do not be afraid, for behold, I bring you good tidings of great joy which will be to all people. For there is born to you this day in the city of David a Savior, who is Christ the Lord. And this will be the sign to you: You will find a Babe wrapped in swaddling cloths, 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, goodwill toward men!”