Isaiah is full of wordplay.  A number of examples come up on chapter 2:5-22.

1. It seems to me that the word for “idol” ( eliyl ) puns on various words for God: el and elohim .   Eliyl means nothing, vapor, empty, which is precisely the opposite of the character of Yahweh.

2. Verse 18 first rhymes then alliterates: eliyl caliyl yachaloph .

3. When Yahweh arises in His power, people who have exalted themselves will be brought low, fleeing into caves and into the dust.  Two words for cave are used in verse 19, and they alliterate: me’arah and mechillah .

4. A pun appears in both verses 19 and 21.  ”Shake terribly” (or “terrify”) is aratz , while the land that is shaken terribly is eretz .  Yahweh is coming to aratz the eretz , to terrify the terrafirma .