As for me, I said, "O LORD, be gracious to me; heal me, for I have sinned against you!" (v4). The psalmist was suffering from a catastrophe; he was spiritually and physically weak, and his enemies were rejoicing. They said that “a deadly thing” was poured out on him, and they “imagined the worst” (v7-8). The psalmist called out to God for healing, not because he was entitled to it (he was at fault, v4), but because he knew God was merciful.
“By this I know that you delight in me …” (v11). Even when we have caused our own troubles, God hears us when we humbly call on Him; He delights in us because we are His.