From Longman Dictionary of Contemporary Englishlet the matter restlet the matter rest (also let it rest)FINISH DOING something to stop discussing or dealing with something The man apologized, but Aunt Matilda refused to let the matter rest. → rest
Examples from the Corpus
let the matter rest• However, she can rest assured that we will not let the matter rest.• I was going to knock for I was still intrigued by him but Benjamin called me so I let the matter rest.• Innocent maintained that Philip should have gone to Rome for absolution but for the moment he let the matter rest.• In her opinion anybody with any sense would let the matter rest there.• Its opponents, however, were unlikely to let the matter rest where it stood in September 1932.• She simply refused to let the matter rest where it.was. 