For the LORD will not cast off for ever:

Jamieson-Fausset-Brown Bible Commentary

31-33. True repentance is never without hope (Ps 94:14).

Matthew Henry's Concise Commentary

3:21-36 Having stated his distress and temptation, the prophet shows how he was raised above it. Bad as things are, it is owing to the mercy of God that they are not worse. We should observe what makes for us, as well as what is against us. God's compassions fail not; of this we have fresh instances every morning. Portions on earth are perishing things, but God is a portion for ever. It is our duty, and will be our comfort and satisfaction, to hope and quietly to wait for the salvation of the Lord. Afflictions do and will work very much for good: many have found it good to bear this yoke in their youth; it has made many humble and serious, and has weaned them from the world, who otherwise would have been proud and unruly. If tribulation work patience, that patience will work experience, and that experience a hope that makes not ashamed. Due thoughts of the evil of sin, and of our own sinfulness, will convince us that it is of the Lord's mercies we are not consumed. If we cannot say with unwavering voice, The Lord is my portion; may we not say, I desire to have Him for my portion and salvation, and in his word do I hope? Happy shall we be, if we learn to receive affliction as laid upon us by the hand of God.