Charles Ellicott 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)

The spirit of slumber.—This phrase, again, has a curious history. Etymologically, the word translated “slumber” would seem to agree better with the marginal rendering, “remorse.” It comes from a root meaning to “prick or cut with a sharp instrument.” There happens to be another root somewhat similar, but certainly not connected, which means “drowsiness,” “slumber.”

Hence, where the word in the text has been used to render the Hebrew word for “slumber,” it has been thought that there was a confusion between the two. It appears, however, from the LXX. usage, that the meaning of “slumber” had certainly become associated with the word used here by St. Paul. From the notion of a sharp wound or blow, the meaning of bewilderment or stupefaction resulting from such a blow was derived; consequently, the word came to signify stupor in general.

The quotation is a free combination of two passages of the LXX. (Isaiah 29:10, and Deuteronomy 29:4), no doubt put together by the Apostle from memory.