A timorous spirit

Isaiah 51:12 I, even I, am he that comforteth you: who art thou, that thou shouldest be afraid of a man that shall die, and of the son of man which shall be made as grass;
13 And forgettest the LORD thy maker, that hath stretched forth the heavens, and laid the foundations of the earth; and hast feared continually every day because of the fury of the oppressor, as if he were ready to destroy? and where is the fury of the oppressor?

Excerpt from Matthew Henry Whole Bible Commentary:

III. The answer immediately given to this prayer (v. 12): I, even, I, am he that comforteth you. They prayed for the operations of his power; he answers them with the consolations of his grace, which may well be accepted as an equivalent. If God do not wound the dragon, and dry the sea, as formerly, yet, if he comfort us in soul under our afflictions, we have no reason to complain. If God do not answer immediately with the saving strength of his right hand, we must be thankful if he answer us, as an angel himself was answered (Zec. 1:13), with good words and comfortable words. See how God resolves to comfort his people: I, even I, will do it. He had ordered his ministers to do it (ch. 40:1); but, because they cannot reach the heart, he takes the work into his own hands: I, even I, will do it. See how he glories in it; he takes it among the titles of his honour to be the God that comforts those that are cast down; he delights in being so. Those whom God comforts are comforted indeed; nay, his undertaking to comfort them is comfort enough to them.

1. He comforts those that were in fear; and fear has torment, which calls for comfort. The fear of man has a snare in it which we have need of comfort to preserve us from. He comforts the timorous by chiding them, and that is no improper way of comforting either others or ourselves: Why art thou cast down, and why disquieted? v. 12, 13. God, who comforts his people, would not have them disquiet themselves with amazing perplexing fears of the reproach of men (v. 7), or of their growing threatening power and greatness, or of any mischief they may intend against us or our people. Observe,

(1.) The absurdity of those fears. It is a disparagement to us to give way to them: Who art thou, that thou shouldst be afraid? In the original, the pronoun is feminine, Who art thou, O woman! unworthy the name of a man? Such a weak and womanish thing it is to give way to perplexing fears. [1.] It is absurd to be in such dread of a dying man. What! afraid of a man that shall die, shall certainly and shortly die, of the son of man who shall be made as grass, shall wither and be trodden down or eaten up? The greatest men, and the most formidable, that are the terror of the mighty in the land of the living, are but men (Ps. 9:20) and shall die like men (Ps. 81:7), are but grass sprung out of the earth, cleaving to it, and retiring again into it. Note, We ought to look upon every man as a man that shall die. Those we admire, and love, and trust to, are men that shall die; let us not therefore delight too much in them nor depend too much upon them. Those we fear we must look upon as frail and mortal, and consider what a foolish thing it is for the servants of the living God to be afraid of dying men, that are here to-day and gone tomorrow. [2.] It is absurd to fear continually every day (v. 13), to put ourselves upon a constant rack, so as never to be easy, nor to have any enjoyment of ourselves. Now and then a danger may be imminent and threatening, and it may be prudent to fear it; but to be always in a toss, jealous of dangers at every step, and to tremble at the shaking of every leaf, is to make ourselves all our lifetime subject to bondage (Heb. 2:15), and to bring upon ourselves that sore judgment which is threatened, Deu. 28:66, 67. Thou shalt fear, day and night. [3.] It is absurd to fear beyond what there is cause: "Thou art afraid of the fury of the oppressor. It is true, there is an oppressor, and he is furious, and he designs, it may be, when he has an opportunity, to do thee a mischief, and it will be thy wisdom therefore to stand upon thy guard; but thou art afraid of him, as if he were ready to destroy, as if he were just now going to cut thy throat, and as if there were no possibility of preventing it." A timorous spirit is thus apt to make the worst of every thing, and to apprehend the danger greater and nearer than really it is. Sometimes God is pleased at once to show us the folly of so doing: "Where is the fury of the oppressor? It is gone in an instant, and the danger is over ere thou art aware." His heart is turned, or his hands are tied. Pharaoh king of Egypt is but a noise, and the king of Babylon no more. What has become of all the furious oppressors of God’s Israel, that hectored them, and threatened them, and were a terror to them? they passed away, and, lo, they were not; and so shall these.