John Chrysostom
"And you have forgotten the consolation," that is, you have let your hands fall and have grown weak. Having set forth consolation from deeds, he now adds besides this consolation from sayings, from the testimony cited: "Do not grow faint," he says, "when He rebukes you." Therefore this is the work of God. It gives no small consolation when we are persuaded that what happened could have come about by God's action, by His permission. Thus Paul also says, "Three times I pleaded with the Lord that it might depart from me. But the Lord said to me, 'My grace is sufficient for you, for My strength is made perfect in weakness'" (2 Cor 12:8-9). Therefore He Himself permits this.