Full Idea
The Stoics call the four bodies - earth and water and air and fire - primary elements.
Gist of Idea
Stoics say earth, air, fire and water are the primary elements
Source
report of Chrysippus (fragments/reports [c.240 BCE], fr 444) by Plutarch - 72: Against Stoics on common Conceptions 1085c
Book Reference
Plutarch: 'Moralia - vol 13 part 2', ed/tr. Cherniss,Harold [Harvard Loeb 1993], p.867
A Reaction
Elsewhere (fr 413) Chrysippus denies that they are all 'primary'. Essentially, though, he seems to be adopting the doctrine of Empedocles and Aristotle, in specific opposition to Epicurus' atomism.