Jerome : (Verse 10, 11.) Who among you fears the Lord, and listens to the voice of his servant? Who walks in darkness, and has no light? Let him trust in the name of the Lord, and rely on his God. LXX: Who among you fears the Lord, and listens to the voice of his servant? Who walks in darkness, and has no light? Let him trust in the name of the Lord, and rely on his God. You have struck me, you have spat on my face: yet I call my persecutors to repentance. For I do not desire the death of a sinner, but only that he should turn back and live (Ezek. 33). And I say: who among you fears the Lord, and listens to the voice of his servant or his child, that is, his Son? of whom one is assumed flesh, the other is of nature. And indeed, let us not think it is enough to fear the Lord, according to what is said in Proverbs: The fear of the Lord is the beginning of wisdom (Prov. 9:10). For perfect love casts out fear, because fear involves punishment. But whoever fears is not perfect in charity. But this fear is placed for timidity and caution; about which we read elsewhere: Blessed is the one who fears everything (Prov. 20), because of caution, that is, because of timidity: those who are commonly called timid in the religion of God. For the Lord protects their path; and guards the way of the timid. Regarding this fear it is written: The fear of the Lord conquers all things. And elsewhere: There is no lack for those who fear Him (Sirach 25:14; Psalms 34:10). Finally, after many steps of virtue, one arrives at this kind of fear of the Lord. For the divine word speaks in the person of a master and father, instructing the disciple and son: If you call upon wisdom and give your voice to understanding, and if you seek it like money and search for it like treasures, then you will understand the fear of the Lord, and you will find the knowledge of God (Prov. 2:3). This is the fear that preserves the souls of the holy ones intact, chaste, and pure, of which it is said, The fear of the Lord remains forever (Ps. 19:9). To whom the divine scriptures exhort us: Fear the Lord, and give him glory (Apoc. XIV, 7). Therefore, whoever fears the Lord in this way, let him listen to the voice of his servant or his child, who walked in darkness and had no light; who had no appearance or glory, but in the likeness of sinful flesh took on the form of a servant, that he might overcome sin in the flesh. Concerning this, it is said, let him hope in the name of the Lord, and rely on his God: so that whatever belongs to human frailty, may be strengthened and sustained by divine majesty. This is in accordance with the Hebrew. However, according to the Septuagint, it is said about sinners, who refused to obey the voice of His Son, and they walk in the darkness of error, and therefore they do not have light. For it was not possible for wisdom to enter into a perverse soul. They did not know or understand, and therefore they walk in darkness. For they did not do the works of the Lord and His commandments, nor did they sow righteousness for themselves, nor did they harvest the vine in order to kindle the light of knowledge for themselves. For whoever desires wisdom, let them keep the commandments, and the Lord will give it to them. Thus it is said to God: Your commandments are a light. And elsewhere: The commandment of the Lord is clear, enlightening the eyes (Ps. 19:9). And it is commanded to the wicked to trust in the Lord, and those who fall into sin rely on his help and support. — Commentary on Isaiah Tertullian : By the mouth of Isaiah also [God] has asked concerning him, "Who is there among you that hears God? Let him hear the voice of his Son." When, therefore, he here presents him with the words, "This is my beloved Son," this clause is of course understood, "who I have promised." For if he once promised and afterwards says, "This is he," it is suitable conduct for one who accomplishes his purpose that he should utter his voice in proof of the promise that he had formerly made; but unsuitable in one who is amenable to the retort, "Can you, indeed, have a right to say, 'This is my son,' concerning whom you have given us no previous information, any more than you have favored us with a revelation about your own prior existence?" — AGAINST MARCION 4.22 Theodoret of Cyrus : It is as a man that he calls himself "Servant," for "although he exists in the form of God, he has assumed the form of a servant." Likewise in the divine Gospel [Christ] says that he has received instruction as to what he should say and proclaim. "They walk in darkness, and there is no light for them." Although the light has risen, as for them, they have clung to the darkness. "Trust in the name of the Lord, and rely on God." [Isaiah] says, if you really put absolute and true hope in God, that will [serve to] sustain you and make you sure. — COMMENTARY ON Isaiah 16:50.10