“suddenly stood before them.” The Greek verb translated “suddenly stood before” is ephistēmi (#2186 ἐφίστημι). Ephistēmi can mean to “be near or close to,” or it can emphasize the suddenness of an event, or it can combine both meanings, as it does in Luke 2:9 and mean “to suddenly be near.” The meaning of standing “near” is in verses such as Luke 2:38 and Acts 22:20, and the meaning of “suddenly” is in verses such as Luke 21:34 and 1 Thessalonians 5:3. The combined meaning of “suddenly be near” occurs here in Luke 2:9, in Luke 24:4 when the angels appeared to the women at the tomb, and also in Acts 12:7 when the angel appeared to Peter in prison.
For the accuracy of the Christmas story and our understanding of angels it is important to note that the angel was standing on the ground in front of the shepherds, he was not flying or floating above them. Alexander MacLaren correctly observes, “The angel speaks by the side of the shepherds, not from above” (Exposition of the Scriptures).
That the angel (and later the army of angels; Luke 2:13) appeared on the ground and not in the air is the way angels generally appear to people in the Bible. For example, we see angels appearing on the ground when the angels came to Sodom and stayed with Lot (Gen. 19:1-3), when one came to Samson’s parents (Judg. 13:3-15), or appeared to Zechariah in the temple (Luke 1:11), or appeared to Mary (Luke 1:26-38), and in many other places as well (cp. Gen. 16:7-11; 19:1-3; 32:2; Exod. 3:2; Num. 22:22-35; Judg. 2:1-5; 6:11-13; 13:3-6; 1 Kings 19:5-7; Dan. 3:24-25, 28; Zech. 1:10-11; 3:3; Matt. 4:11; 28:2-6; Luke 1:11-20, 26-38; John 20:12; Acts 5:19; 10:3-7; 11:13; 12:7-10; Rev. 22:8-9).
Although angels can appear to people while being in mid-air (1 Chron. 21:16), that is not usual and not what happened here in Luke 2:9. It was the sudden presence of the angel and the bright light of God that frightened the shepherds, not the fact that the angel was suspended in the air. Furthermore, the army of angels that suddenly appeared “with the angel” were on the ground also (Luke 2:13), just as they were on the ground when God’s angel army filled the hills around Elisha (2 Kings 6:17).
What an honor and privilege it must have been for those angels to be present at the birth of the Messiah. They had put up with the constant flow of evil coming from the Devil and his demons for thousands of years and were very aware that God’s whole creation was in pain due to the Devil and the consequences of the Fall. Now at last they knew the Messiah was born and that deliverance from evil and the restoration of all things was in sight.
“frightened with great fear.” In the Greek text this phrase is the figure of speech polyptoton; the same root word used with different inflections, in this case one being a noun and the other a verb (Cp. Bullinger, Figures of Speech).