A.T. Robertson Commentary Romans 11:8

"according as it is written, God gave them a spirit of stupor, eyes that they should not see, and ears that they should not hear, unto this very day." — Romans 11:8 (ASV)

A spirit of stupor (πνευμα κατανυξεως). The quotation is a combination of De 19:4; Isaiah 29:10; 6:9f. This phrase is from Isa 29:10. Κατανυξις is a late and rare word from κατανυσσω, to prick or stick (Acts 2:37), in LXX, here only in N.T., one example in PelagiaLegende. The torpor seems the result of too much sensation, dulled by incitement into apathy.

That they should not see (του μη βλεπειν). Genitive articular infinitive of negative purpose.

That they should not hear (του μη ακουειν). So here also. See Stephen's speech (Acts 7:51f.).