Romans 10:18

But I say. The Jews might claim that they had not had opportunity to hear, and hence had not accepted the gospel. Paul proceeds to disprove this claim.

Have they not heard? Or, “Is it that they did not hear?” or “Did they fail to hear?” The Greek construction of this question indicates that a negative answer is expected and that the excuse cannot be admitted. “They” refers to the “not all” of v. 16, meaning particularly the unbelieving Jews.

Yes verily. This is Paul’s emphatic correction to the suggestion that they had not heard the message. He asserts, on the contrary, that the gospel has gone to all the world, and he makes his assertion in the words of Ps. 19:4.

Sound. Gr. phthoggos, an onomatopoeic word (pronounced “phthongos”), imitating the sound made by the vibration of a musical instrument or the human voice (cf. 1 Cor. 14:7). In the OT this verse reads “measuring line” rather than “sound” (see on Ps. 19:4). According to the psalmist, “their sound” is the voice of nature, the silent witness with which “the heavens declare the glory of God; and the firmament sheweth his handywork” (Ps. 19:1). The psalmist compares the revelation of God in His works (Ps. 19:1-6) with the special revelation of Himself through His word (Ps. 19:7-11). Paul sees in this a representation of the worldwide preaching of the gospel, and he uses the words of the psalmist to describe how the “sound” of the preachers of the word of faith has gone out “into all the earth.”

The world. Gr. oikoumene, “the inhabited world” (see on Luke 2:1). At the time of the writing of this epistle, the gospel had apparently not been preached literally everywhere, for it had evidently not yet been taken to Spain (see Rom. 15:20, 24, 28). However, the message of faith had already been spread so widely throughout the world that Paul is justified in making such a broad general statement. In fact, within his generation the gospel was carried “to every creature which is under heaven” (Col. 1:23; cf. Ed 96). Moreover, the message was always taken “to the Jew first” (Acts 9:20; 11:19; 13:5; 14:1; 17:1,2, 10; 18:4, 19; 28:17; Rom. 1:16), and it is probably Paul’s primary purpose in this chapter to show that no Israelite can excuse himself upon the plea that he had never heard the gospel.