The Son of God, who existed as such, from everlasting - John Gill

"...And declared to be the Son of God, etc... Not made as he is said to be before, when his incarnation is spoken of; nor did he begin to be the Son of God, when he was made of the seed of David, but he, the Son of God, who existed as such, from everlasting, was manifested in the flesh, or human nature: and this his divine sonship, and proper deity, are declared and made evident..." -John Gill, commenting on Romans 1:4