en_tn/ecc/03/01.md

General Information:

The writer uses merisms to describe various aspects of life from one extreme to the other. (See: rc://en/ta/man/jit/figs-merism)

every matter

"every event" or "every activity" or "everything that can happen"

under heaven

This refers to things that are done on earth. See how you translated this in Ecclesiastes 1:3. Alternate translation: "on the earth" (See: rc://en/ta/man/jit/figs-idiom)