Psalms 109:21 - Matthew Poole's English Annotations on the Holy Bible

Do thou for me, to wit, what I desire, which he expressing the next clause. Or, do thou act for me; be not or still, but stir up thyself to work on my behalf. For my name's sake; for the glory of thy faithfulness, which highly concerned in giving me the deliverance which thou hast promised to me. Thy mercy is good, i.e. gracious, ready to do good to all, but especially to those that and fear thee. As sin is said to be sinful, Ro 7, so God's mercy may be said to be merciful, to wit, in degree, and above the mercy of all the creatures