Something that has long interested me, ever since I obtained a copy of Dr. Rudd's Goetia, has been the inclusion of various Psalms of David in relation to the spirits. I am curious about a few things: the origin of their correspondence (when did they first appear alongside the spirit sigils?), the reason for their omission in other editions (were they deliberately withheld or did Skinner and Rankine have access to manuscripts which others previously did not?), and most interestingly to me, their relation to the nature of the spirits themselves. In addition, I have had a much greater success rate in my evocations ever since I began using the psalms in combination with the seals of the spirits...I personally attribute this to: 1. Perhaps the psalms are the "missing key" to the proper evocation of these spirits. 2. I feel as though the psalms have given me greater insight into the nature, powers, and offices of the spirits.
I have a pet theory that the corresponding psalms can actually give insight into the nature of the spirits, even if it through an inverse correlation. For example, while one of the reputed powers of Bael is "invisibility" (not to bring up a debate about what that means specifically, such as in my previous thread, but simply for the sake of example), the corresponding psalm given in Dr. Rudd's edition is "Tu Domine susceptor meus es gloria mea et exaltans Caput meum." and this is translated in the same book as "Thou, O Lord, art my guardian, and exaltest my head." (Psalm 3:5)
I am interested to hear any and all of your thoughts on this matter.