Isaiah 40:31

But they that wait upon the Lord -The word rendered ‘wait upon’ here (fromקוהqâvâh), denotes properly to wait, in the sense of expecting. The phrase, ‘to wait on Yahweh,’ means to wait for his help; that is, to trust in him, to put our hope or confidence in him. It is applicable to those who are in circumstances of danger or want, and who look to him for his merciful interposition. Here it properly refers to those who were suffering a long and grievous captivity in Babylon, and who had no prospect of deliverance but in him. The phrase is applicable also to all who feel that they are weak, feeble, guilty, and helpless, and who, in view of this, put their trust in Yahweh.