Them that wait on thee, i.e. thy godly people, who rely upon thy promises which thou hast made to all thine in general, and to me in a special manner, wherein they also are concerned. Ashamed, i.e. frustrated of their just hopes; which will make them ashamed, either to look upon God, or to look upon their enemies, when they shall reproach them for their confidence in God. For my sake; either,
1. For the sake of my sins last mentioned; let not all good men suffer for my sins. Or,
2. Because of my sad disappointments. For if they see me rejected and forsaken of God, whom they have esteemed a great example of faith, and prayer, and all virtue and piety, they will be exceedingly discouraged by this example; which will tend much to thy dishonour and disservice.