Ellicott's Commentary On The Whole Bible
Psalms 143 - Introduction
CXLIII.
This psalm is chiefly interesting as an instance of the way in which the deeper religious life of the post-exile times was upheld and cherished by the experience of past times and the faith of older generations as it had found expression in prophecy and song. For, as the Notes will show, there is hardly a phrase which is not derived from some older source — a fact which at once disposes of the inscription.
Probably it is not an individual, but the community, which thus under affliction confesses its sin and comforts itself with reflections on the past.