Albert Barnes Commentary Romans 10:8

"But what saith it? The word is nigh thee, in thy mouth, and in thy heart: that is, the word of faith, which we preach:" — Romans 10:8 (ASV)

But what does it say? That is, what is the language of the doctrine of justification by faith? Or what is to be done according to that doctrine?

The word is near you. This is still a use of the language of Moses (Deuteronomy 30:14). The meaning is, the doctrine is not difficult to understand and embrace. What is near us may be easily obtained; what is remote, with difficulty. The doctrine of Moses and of the gospel was near; that is, it was easily obtained, embraced, and understood.

In your mouth. This is taken from the Septuagint (Deuteronomy 30:14). The meaning is that the doctrine was already so familiar and so well understood that it was actually in their mouth; that is, their language, their common conversation. Moses had so often inculcated it, that it was understood and talked about by the people, so that there was no need to search in distant lands to obtain it. The same was true of the gospel. The facts were so well known by the preaching of the apostles, that they might be said to be in every man's mouth.

In your heart. The word heart is used in many different ways in the sacred Scriptures. As used by Moses in this place, it evidently means that his doctrines were in their mind, or were a subject of meditation and reflection. They already possessed them, and talked and thought about them, so that there was no need of going to distant places to learn them. The same was true of the doctrine requiring faith in Christ. It was already among them by the preaching of the apostles, and was a subject of conversation and of thought.

That is. This is the use which the apostle makes of it; not that Moses referred to the gospel. His language conveys the main idea which Paul wished to convey, that the doctrine was plain and intelligible.

The word of faith. The doctrine which requires faith, i.e., the gospel. (Compare to 1 Timothy 4:6). The gospel is called the word of faith, the word of God, as being that which was spoken, or communicated by God to man (Romans 10:17; Hebrews 6:5; Hebrews 11:3).

Which we preach. Which is proclaimed by the apostles and made known to Jews and Gentiles. As this was now made known to all, as the apostles preached it everywhere, it could be said to be near them; there was no need of searching other lands for it, or regarding it as a hidden mystery, for it was plain and manifest to all. Its simplicity and plainness he proceeds immediately to state.