Left: word 讠/言 (sound waves out of a mouth 口), right: circumference 周 (The frame 冂 becomes happy 吉 with the circumference of a circle.) [joy 吉 = simplification of happy 喜, where the scholar 士 has beans 豆 in his mouth 口 and is happy.]
Mnemonic
Words in their circumference are in harmony, like a: tone/tune.
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