Job's friends' initial reaction of being appalled at his appearance directly fulfills the call in 21:5 — a strong narrative parallel within Job.

Job's description of skin and bones explains why people should be appalled at his appearance — a direct physical parallel.

In Job 40:4, Job himself lays hand on mouth before God, using the same gesture of silence he demands from others.

In Job 29:9, princes once laid hand on mouth in respect; now Job asks for that same gesture in horror at his plight.

Job says the upright are appalled at his condition, reinforcing the same call for astonishment in 21:5 — a thematic parallel.

Micah 7:16 describes nations laying hand on mouth in shame, similar gesture of awe/reaction to divine action.