But while he thought on these things; when (Revised Version); ταῦτα δὲ αὐτοῦ ἐνθυμηθέντος. The tense lays stress, not on the continuance of his meditation (contrast Acts 10:19), but on the fact that the determination to which he had already come (vide supra) was already in his mind at the time when the following event happened. "These things;" his determination and its causes. Behold; unexpectedly. Though common in St. Matthew, it never lacks the connotation of surprise. The angel of the Lord; an angel of the Lord (Revised Version). In Mary's case it was the angel Gabriel (Luke 1:26); but here not defined (so in Matthew 2:13, Matthew 2:19; Luke 1:11; Luke 2:9). (On angels, of especially Dorner, 'System.,' 2.96.) Appeared unto him in a dream. Joseph received his communications by dream (Matthew 2:13, Matthew 2:19, Matthew 2:22); to Mary, doubtless the more holy person, the vision was vouchsafed to her bodily eyes. If Joseph, as seems probable, was old, we here have a beginning of the fulfilment of the promise concerning Messianic times, "Your old men shall dream dreams" (Joel 2:28). Saying, Joseph, thou son of David. In reminding Joseph of the greatness of his ancestry, the angel probably desired
Fear not to take unto thee Mary thy wife (2 Samuel 7:15, note). For that which if conceived in her ("borun," Wickliffe; quod natum est, Vulgate); "Gr. begotten", for γεννηθέν generally refers to the father rather than the mother (yet see Matthew 11:11), and here lays special stress on the Divine origin. Is of the Holy Ghost. "Of Spirit (not flesh), and that the Holy Spirit ( ἐκ πνεύματός ἐστιν ἁγίου)" (2 Samuel 7:18, note).