You have heard my vows: The psalmist's vows might be part of ceremonial sacrifices (Psalms 66:13–15; 76:11; 116:14, 18). He praises and thanks God for rescuing him.
The inheritance refers to the promise of the land (see Psalm 60), the sacredness of the temple, the joy of God's presence (Psalm 119:111), or any similar reward (Psalms 16:6; 37:9, 11, 18, 22, 29, 34; 127:3).