In thee, O Lord, do I put my trust. If prayer to God for aid in a special time of trouble is the main object of the psalm, the expression of full trust in God is a secondary object, and is maintained throughout (see Psalms 31:3-8, Psalms 31:14, Psalms 31:19-21, Psalms 31:24).
Notwithstanding the extremity of his danger, his belief is firm in the coming overthrow of his enemies, and in his own deliverance and restoration. Let me never be ashamed (comp. Psalms 31:17, where the idea is expanded).
David's enemies having come to an open rupture with him, and appealed to arms (2 Samuel 15:10-12; 2 Samuel 17:24-26), one party or the other must of necessity be put to shame. Here he prays that it may not be himself; in Psalms 31:17 he goes a step further, and asks that the shame may fall upon his enemies.
Deliver me in thy righteousness. Seeing that my cause is the righteous one.