“And there appeared unto him an angel of the Lord standing on the right side of the altar of incense.”
Luke 1:11 — Greek Interlinear
Church Fathers on Luke 1:11
When Zacharias entered into the temple to offer up prayers to God for all men, interceding between God and man, he saw an angel standing within, as it is said, And there appeared to him an angel.
It is well said that there appeared an angel to Zacharias, who suddenly beheld him; and this is the expression especially used by Divine Scripture with respect to angels or God, that what cannot be seen beforehand may be said to appear. For things which are the objects of our senses are not seen as He is seen, Who is seen only as He will, and Whose nature is not to be seen.
And we speak thus not only of the present time, but also of the future. When we shall have passed from the world, God will not appear to all men, nor will the angels, but to him only who has a clean heart. The place will neither hinder nor serve any one.