Full Idea
One of the best reliques which a devotee could procure would be the handiwork of a saint, because they were once at his disposal, and were moved and affected by him.
Clarification
An example of ideas associated by causation
Gist of Idea
An object made by a saint is the best way to produce thoughts of him
Source
David Hume (Enquiry Conc Human Understanding [1748], V.II.43)
Book Reference
Hume,David: 'Enquiries Conc. Human Understanding, Morals', ed/tr. Selby-Bigge/Nidditch [OUP 1975], p.53