A.T. Robertson Commentary Luke 1:31

"And behold, thou shalt conceive in thy womb, and bring forth a son, and shalt call his name JESUS." — Luke 1:31 (ASV)

Conceive in thy womb (συλλημψη εν γαστρ). Adding εν γαστρ to the verb of 1:24. Same idiom in Isa 7:14 of Immanuel.

Jesus (Ιησουν). As to Joseph in Mt 1:21, but without the explanation of the meaning. See on Matthew.