Tertullian

“ In order, therefore, that He who was already the Son of God—of God the Father’s seed, that is to say, the Spirit—might also be the Son of man, He only wanted to assume flesh, of the flesh of man [3] without the seed of a man ”

“ As, then, before His birth of the virgin, He was able to have God for His Father without a human mother, so likewise, after He was born of the virgin, He was able to have a woman for His mother without a human father. He is thus man with God, in short, since He is man’s flesh with God’s Spirit [6] —flesh (I say) without seed from man, Spirit with seed from God. For as much, then, as the dispensation of God’s purpose [7] concerning His Son required that He should be born [8] of a virgin, why should He not have received of the virgin the body which He bore from the virgin? ”

“ Besides, as He was in possession both of flesh and of Spirit, He cannot possibly, when speaking of the condition of the two substances which He Himself bears, be supposed to have determined that the Spirit indeed was His own, but that the flesh was not His own. Forasmuch, therefore, as He is of the Spirit He is God the Spirit, and is born of God; just as He is also born of the flesh of man, being generated in the flesh as man. [14] ”