Translation:

40. Canst thou then make the deaf to hear or give direction to the blind or to such as (wander) in manifest error?

Notes (Tafseer)

4643. Cf. xxx. 52-53. The evil go headlong into sin, and sink deeper and deeper until their spiritual faculties are deadened, and no outside help can bring them back. Allah's grace they have rejected.

4644. There is hope for a person who wanders in quest of truth, and even for one who wanders through mistake or by weakness of will. But there is none for one who, by deliberate choice, plunges into "manifest error", i.e., error which any one can see.