Adam Clarke on Isaiah 60:22

I the Lord will hasten it in his time - There is a time set for the fulfillment of this prophecy: that time must come before it begins to take place; but when it does begin, the whole will be performed in a short space. It is not, therefore, the time determined for the event that shall be hastened, but all the circumstances of the event; all the parts of the prediction shall be speedily completed. I the Lorde in hys tyme sodeynly schal boun thys. - Old MS. Bible. And because it is the Lord, therefore it will be done: for although it be difficult, he is almighty.