Romans 10:18

This rhetorical question suggests the possibility that Israel’s rejection of her Messiah may have been due to a failure to get the message to the Jews (Romans 10:14). However, Paul’s quotation of Psalms 19:4 clarifies that they had heard. Every human being hears the testimony of nature (ch. 1), and all Israel had heard the special revelation of God concerning His Son from the prophets. They could not plead ignorance as a nation.

"But perhaps it would be simpler to think that Paul engages in hyperbole, using the language of the Psalm to assert that very many people by the time Paul writes Romans have had opportunity to hear. It cannot be lack of opportunity, then, that explains why so few Jews have come to experience the salvation God offers in Christ." [Note: Moo, p. 667.]