Therefore, he was a prophet, for he knew that God had sworn an oath to him about the fruit of his loins, about the One who would sit upon his throne
Other versions
King James Version
Therefore being a prophet, and knowing that God had sworn with an oath to him, that of the fruit of his loins, according to the flesh, he would raise up Christ to sit on his throne;English Standard Version
Being therefore a prophet, and knowing that God had sworn with an oath to him that he would set one of his descendants on his throne,New International Version
But he was a prophet and knew that God had promised him on oath that he would place one of his descendants on his throne.