Son of God is more egytpian then semetic, it appears in the Torah as Adam, because God was is true father, Egytpian Equivilent is "Son of RA" a title that all Egytpian pharoahs have, because the egyptian believed the pharoahs were an incarnation of Horus, who was the first pharoah of egypt. Horus was the Son of God(ra) and Mari-Hathor - Infact the term Hathor means House of God, were Pharoahs are said te be born from, Hathor as the same meaning of bethany and bethel eg Mary of bethany = Meri-Hathor of egypt.
thus the Origin of the term "Son of God"