Isaiah 57:16

For I will not contend for ever - I will not be angry with my people forever, nor always refuse to pardon and comfort them (see Psalms 103:9). This is to be regarded as having been primarily addressed to the Jews in their long and painful exile in Babylon. It is, however, couched in general language; and the idea is, that although God would punish his people for their sins, yet his wrath would not be perpetual. If they were his children, he would visit them again in mercy, and would restore to them his favor.

For the spirit should fail before me - Critics have taken a great deal of pains on this part of the verse, which they suppose to be very obscure. The simple meaning seems to be, that if God should continue in anger against people they would be consumed. The human soul could not endure a long-continued controversy with God. Its powers would fail; its strength decay; it must sink to destruction. As God did not intend this in regard to his own people; as he meant that his chastisements should not be for their destruction, but for their salvation; and as he knew how much they could bear, and how much they needed, he would lighten the burden, and restore them to his favor. And the truth taught here is, that if we are his children, we are safe. We may suffer much and long. We may suffer so much that it seems scarcely possible that we should endure more. But he knows how much we can bear; and he will remove the lead, so that we shall not be utterly crushed. A similar sentiment is found in the two following elegant passages of the Psalms, which are evidently parallel to this, and express the same idea:

But he being full of compassion,

Forgave their iniquity, and destroyed them not;

Yea many a time burned he his anger away,

And did not stir up all his wrath.

For he remembered that they were but flesh;

A wind that passeth away and returneth not again.

Psalms 78:38

He will not always chide;

Neither will he keep his anger forever.

Like as a father pitieth his children,

So the Lord pitieth them that fear him.

For he knoweth our frame;

He remembereth that we are dust.

Psalms 103:9, Psalms 103:13

The Hebrew word which is rendered here ‘should fail’ (עטף ‛âṭaph), means properly to cover, as with a garment; or to envelope with anything, as darkness. Then it is used in the sense of having the mind covered or muffled up with sorrow; and means to languish, to be faint or feeble, to fail. Thus it is used in Psalms 61:2; Psalms 107:5; Psalms 142:3; Lamentations 2:11, Lamentations 2:19; Jonah 2:7. Other interpretations of this verse may be seen in Rosenmuller; but the above seems to be the true sense. According to this, it furnishes ground of encouragement and comfort to all the children of God who are afflicted. No sorrow will be sent which they will not be able to endure, no calamity which will not be finally for their own good. At the same time, it is a passage full of alarm to the sinner. How can he contend forever with God? How can he struggle always with the Almighty? And what must be the state in that dreadful world, where God shall contend for ever with the soul, and where all its powers shall be crushed beneath the vengeance of his eternal arm!