Hear my prayer, O Lord, give ear ... - See Psalms 4:1, note; Psalms 5:1, note.
In thy faithfulness answer me - That is, Show thy faithfulness to thy promises. God had made gracious promises to David (compare Psalms 89:19-37), and he now pleads that he would remember those promises, and accomplish in his behalf what he had said he would. God has also made gracious promises to his people, and they may always plead those promises as a reason why they should be heard, and why their prayers should be answered.
And in thy righteousness - Compare Psalms 31:1. In thy disposition to do right; to vindicate a righteous cause; to interpose when wrong is done. We, though sinners before God, may feel that our cause is a just one as toward our fellowmen, and, when wronged, we may ask God to interpose, as a righteous God, in our behalf. We cannot, however, ask him to save us on the ground of our righteousness toward him, for we have no such righteousness. See Psalms 143:2.