Charles Ellicott Commentary Luke 1:11

"And there appeared unto him an angel of the Lord standing on the right side of altar of incense." — Luke 1:11 (ASV)

The altar of incense.—The altar stood just in front of the veil that divided the outer sanctuary from the Holy of Holies. It was made of shittim wood, and overlaid with gold, both symbols of incorruption (Exodus 30:1–7; Exodus 40:5; Exodus 40:26). Its position connected it so closely with the innermost sanctuary that the writer of the Epistle to the Hebrews (Hebrews 9:4; but see Note there) seems to consider it as belonging to that, and not to the outer. It symbolized accordingly the closest approach to God which was then possible for anyone but the high priest, when, in his typical character, he entered the Holy of Holies on the day of Atonement.