Psalms 89:26

26.He shall cry to me, Thou art my Father. In this verse it is declared, that the chief excellence of this king will consist in this, that he will be accounted the Son of God. This indeed is a title of honor, which is applied to all whom God ordains to be kings, as we have seen in a previous psalm,

“I have said, Ye are gods; and all of you are children of the Most High:”
(Psalms 82:6)

but in the passage before us, something special is expressed of the holy king whom God had chosen, and it is intended to say, that he will be the son of God in a different sense. We shall immediately see in the subsequent verse, how he is placed in a higher rank than the kings of the earth, although they may sway the scepter over a larger extent of country. It was therefore a privilege peculiar to only one king in this world, to be called the Son of God. Had it been otherwise, the apostle reasoned not only inconclusively but absurdly, in quoting this text as a proof of the doctrine, that Christ is superior to the angels:

“I will be to him a Father, and he shall be to me a Son,”
(Hebrews 1:5.)

Angels, and kings, and all who are regenerated by the Spirit of adoption, are called sons of God; but David, when God promises to take him for his son, is, by singular prerogative, elevated above all others to whom this designation is applied. This is still more apparent from the following verse, in which he is called God’s first-born, because he is higher than all the kings of the earth; and this is an honor which transcends all the dignity both of men and angels. If it is objected, that David being a mortal man could not be equal to the angels, the obvious answer is, that if he is considered in himself, he cannot justly be elevated to the same rank with them, but with the highest propriety he may, in so far as for a time he represented the person of Christ.