Jamieson, Fausset and Brown on Matthew 1:18

Mt 1:18-25. Birth of Christ.

18. Now the birth of Jesus Christ was on this wise--or, "thus."

When as his mother Mary was espoused--rather, "betrothed."

to Joseph, before they came together, she was found--discovered to be.

with child of the Holy Ghost--It was, of course, the fact only that was discovered; the explanation of the fact here given is the Evangelist's own. That the Holy Ghost is a living conscious Person is plainly implied here, and is elsewhere clearly taught (Ac 5:3, 4, &c.): and that, in the unity of the Godhead, He is distinct both from the Father and the Son, is taught with equal distinctness (Mt 28:19; 2Co 13:14). On the miraculous conception of our Lord, see on Lu 1:35.