I have been working on a commentary on the Psalms. I have decided to compile some helpful links that I discovered during my research. It includes a mix of exegetical and sermonic links. Here is what I have for Psalm 31 (in no particular order). Feel free to mention any that you find helpful in the comments section.
Literary analysis of Psalm 31: http://psalmsstudy.com/psalms-literary-analysis-by-chapter/literary-analysis-psalm-31
Analysis by C. J. Labuschagne: https://www.labuschagne.nl/ps031.pdf
William Barrick’s notes: https://drbarrick.org/files/studynotes/Psalms/Ps_031.pdf
Sermon Writer: https://sermonwriter.com/biblical-commentary/psalm-31-commentary
Steven J. Cole, “Psalm 31: The Remedy for Stress”: https://bible.org/seriespage/psalm-31-remedy-stress