For how wondrously doth this stablish our faith when we believe in a Saviour that is God; the Son of God, Jesus Christ by eternal generation. In a word, here are these prerogatives of Christ’s generation from all other sons whatsoever. Other fathers are before their sons, this Son of God was eternal with his Father. Other fathers have a distinct essence from their sons, the father is one, and the son another; they have distinct existences; but here there is one common essence to the Father and the Son. Other fathers beget a son without them, but this Father begets his Son within him. It was an inward work. So it is a mystical divine generation, which indeed is a subject of admiration rather than of explication, that Jesus Christ is the Son of God and the Son of man. – Richard Sibbes, An Exposition of 2 Corinthians 1