Cyril of Alexandria : For the law was not a perpetual and immoveable law, but it remained in force only as long as the time of its imposition. As the most wise Paul said, "For the former and ancient command has a gap whose filling is to be sought in the second, that is, the new has many things quite different from the old." …That second one is the eternal covenant, and that he fulfilled it for those approaching him by faith is confirmed when it immediately adds, "the holy trustworthy things of David." This concerns the announcements about the Savior of us all, Christ, which are declared to be given to those who are attentive among the nations, or it means the divine and sacred prophecies of Christ, who was born from the seed of David according to his humanity. These are called "holy," for they make perfect those in whom they dwell, just as the fear of God is called "pure" because it is purifying and the gospel word is called "life" because it gives life.… This is the power through Christ of these prophecies.… — COMMENTARY ON Isaiah 5:2.55:1-5 Jerome : The promise of all good things is eternal life. But if you wish to hear and your soul will live forever, I will make with you an everlasting covenant, the faithful mercies of David.… But this pact, which the Lord promises, will not be brief and of one time, as it was for the people of the Jews, but it will remain forever, so that the true David may come, and what has been promised from the person of God may be fulfilled in the Gospel: "I have found David my servant, with my holy oil I have anointed him." … Whom, according to Ezekiel, David, who has been sleeping for many centuries, calls his servant and shepherd, saying: "I will raise up for you one shepherd, my servant David." — Commentary on Isaiah Theodore of Heraclea : The Lord God, ever compassionate, is ready to bring people to good things, and he promises to give not only good things in the present but also the enjoyment of eternally good things in the hereafter. For he demands nothing other than a ready listener, one who takes in his words and is quick to respond willingly to his voice. To attend with the ears in the sense of physical hearing is only what seems to be meant here. For attending with the eyes, we are not able to hear with these, and we cannot see as we listen with our ears. The same is true in the case of the other senses. From this we can assume that we pay attention with the eyes of the mind and are able to listen with the ears. For the soul is single and with one form by nature, and with one power [it] is able to listen and to see. But the mass of your sins and ungodliness constricts you and hinders you from fleeing to him. But there would be no such great obstacle if you desire that mercy beyond words; for then such evils of yours would not defeat and overcome his compassion. For God is great in pity, and he will provide forgiveness for your sins and so will show you to be pure, so that no trace of your former sins will remain. — FRAGMENTS ON ISAIAH Theodoret of Cyrus : I will fulfill these covenants that had been made to David for them, clothing the human nature from the line of David according to the promise and bringing forth the New Testament. — COMMENTARY ON Isaiah 17:55.2-3