Musar for Isaiah 66:10

Therefore, one should concern himself and weep because of the Torah which is forgotten and should lament for those who revere God, Blessed be He, and have been rejected by men, and should complain bitterly over the little piety that exists and over Israel, the people of the Lord, trodden under foot, and he should raise Jerusalem over his greatest joy and may he merit to behold her joy, as it is written : "Rejoice for joy with her; all ye that mourn for her" (Is. 66:10).