The Rythlondar Riddle

In re-reading the Ryth Chronicle (Here), I was reminded of the 'Weir Riddle'.  In an expedition to the Weir in October 2775, a party discovered the "lesser treasure of Felsicon" behind a secret door on the second level (Ryth Chronicle, Number III, October 1976, p. 6).  Behind the door, in a small room, were four ornate chests.   The party learned that only the "proper" one could be opened on pain of a curse.  To determine the chest to open, the party needed to solve a riddle: "What do a patient assassin and a sleeping glutton have in common"?

Answers?