How do I solve 3 down in Daily Telegraph Cryptic 3371?

Question

Accepted Answer

3 down reads "Descend from there, dear Lord!" (4,3,2 letters); the answer is COME OFF IT. It's a double-definition clue: two separate definitions of the same word sit side by side. No wordplay split and no indicators — both halves of the clue define the answer. The full step-by-step breakdown is on this page.

Descend from there, dear Lord! (4,3,2)

3D — Descend from there, dear Lord! (4,3,2) — COME OFF IT