Guide to the Psalms by William Graham Scroggie and published by Kregel Publications.
Scroggie's psalm-by-psalm commentary provides a comprehensive treatment of each of the Old Testament's songs. Originally published in four volumes, this complete and unabridged volume gives you an exposition of each psalm and examines its poetic form, outline, and historical setting. But that's only the beginning! He also supplies homiletical illustrations, meditations, five indexes, 12 appendices that clarify difficult textual questions, and other literary devices in the Psalms.
Also included are homiletical illustrations and devotional thoughts for each of the Psalm.