Full Idea
When an object is present to memory or senses, custom carries the imagination to that object which is usually conjoined with it. This carries a feeling different from the loose reveries of fantasy, and in this consists the whole nature of belief.
Gist of Idea
Belief is just a particular feeling attached to ideas of objects
Source
David Hume (Enquiry Conc Human Understanding [1748], V.II.39)
Book Reference
Hume,David: 'Enquiries Conc. Human Understanding, Morals', ed/tr. Selby-Bigge/Nidditch [OUP 1975], p.48