But thou hast... — The Authorised version represents the mourner as falling back from the hopeful prayer into the depths of despair. For “but” we should, however, read unless. The hypothesis of utter rejection is just stated as the only thing that could prevent renewal and restoration, and it is stated as per impossible; God has not rejected, and therefore He will renew.
It may be noted that in Synagogue use, and in many MSS., Lamentations 5:21 is repeated after Lamentations 5:22, so that the book may not end with words of so terrible a significance. The same practice obtained in the case of the last verse of Isaiah, Ecclesiastes, and Malachi.