The interpretation timeline
Deuteronomy 30:14 Douay-Rheims

But the word is very nigh unto thee, in thy mouth and in thy heart, that thou mayst do it.

A.D. 215 – 1849 4 witnesses

Patristic

before A.D. 750
215
A.D.
c. A.D. 150–215
“"Anyone who tries to act high-handedly annoys God," says Scripture. For bombast is a spiritual vice. Scripture tells us to repent from it as from the other vices by turning from disharmony and by linking ourselves to a change for the better through the three instruments of mouth, heart and hands.”

Scholastic

c. 1100 – 1500
1105
A.D.
Rashi Jewish
1040–1105
כי קרוב אליך BUT [THE WORD] IS [VERY] NEAR UNTO YOU — the Torah has been given to you in writing and orally.”

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“But the word is very nigh unto thee,.... In the ministration of it by those who clearly, plainly, and faithfully preach it, and in the application of it by the Spirit of God to the heart; and in the gracious experience converted persons have of the power and efficacy of it in them, and of the comfort they receive from it: in thy mouth, and in thy heart, that thou mayest do it; in the mouth by confession, being not ashamed to own it, and profess it before men; and in the heart, where it is come with power, has a place, and works effectually, and is cordially believed, and comfortably experienced; and when this is the case, its ordinances will be faithfully kept as delivered, and cheerfully submitted to.”
Source
1849
A.D.
1774–1849
“Heart. Septuagint add, “and in thy hands.” Thou art often obliged to talk about the law, and to learn it by heart. Nothing hinders thee, with the grace of God, from putting it in practice. (Calmet) — No teacher could more plainly inculcate the liberty of the human will. (Theodoret, q. 38.; St. Augustine, de Nat. 69.; St. Ambrose; &c.) (Worthington)”
Source
Modern · 1953 →

The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.