John Calvin Commentary Isaiah 49:2

"and he hath made my mouth like a sharp sword; in the shadow of his hand hath he hid me: and he hath made me a polished shaft; in his quiver hath he kept me close:" — Isaiah 49:2 (ASV)

And he has placed my mouth as a sharp sword; he employs a twofold comparison, that of “a sword” and of “a quiver,” to denote the power and energy of the doctrine. He shows why he was called, and why he was honored by a name so excellent and illustrious: specifically, that he may teach, for this is what he means by the word “mouth.” Christ has therefore been appointed by the Father, not to rule in the manner of princes, by the force of arms, and by surrounding himself with other external defenses, to make himself an object of terror to his people. Instead, his whole authority consists in doctrine, in the preaching of which he wishes to be sought and acknowledged, for nowhere else will he be found. He asserts the power of his “mouth”—that is, of the doctrine which proceeds from his mouth—by comparing it to “a sword,” for

the word of God is quick and powerful, and sharper than any two-edged sword, and piercing even to the dividing of the soul and the spirit, and of the joints and marrow, and is a discerner of the thoughts and intentions of the heart (Hebrews 4:12).

And has made me as a polished arrow. He now compares his mouth to “an arrow,” because it strikes not only nearby, but also at a distance, and reaches even those who appear to be far away.

In his quiver has he hid me. After speaking of the efficacy of doctrine, Isaiah adds that God, by his power, protects Christ and his doctrine, so that nothing can stop his course. And this was very necessary to add, for as soon as the mouth of Christ is opened—that is, as soon as his Gospel is preached—adversaries rise up on all sides, and innumerable enemies league together to crush it. Consequently, the efficacy which he ascribes to doctrine would not be sufficient if his protection were not also added to drive away adversaries.

Besides, the present question is not about the person of Christ, but about the whole body of the Church. We must indeed begin with the Head, but we must next come down to the members. And what is affirmed here concerning Christ must also be applied to all ministers of the Word, for to them is given such efficacy of the Word that they may not idly beat the air with their voices, but may reach the hearts and touch them to the quick.

The Lord also causes the voice of the Gospel to resound not only in one place, but far and wide throughout the whole world. In short, because he faithfully keeps them under his protection, though they are exposed to many attacks and are assaulted on every side by Satan and the world, they still do not swerve from their course. We ought to know this well from experience, for every one of them would have long ago been ruined by the conspiracies and snares of adversaries if the Lord had not defended them by his protection. And indeed, amid so many dangers, it is almost miraculous that a single preacher of the Gospel is permitted to remain. The reason for this is that the Lord guards them by his shadow and “hides them as arrows in his quiver,” so that they may not be exposed to the assaults of enemies and be destroyed.