Theodoret of Cyrus: New Covenant is Last Covenant

He called the new covenant eternal for reason of there being no further one after it; in case anyone think it would also be brought to an end through some other covenant, he was right to bring out its having no end.

- Theodoret of Cyrus (around A.D. 393 to around A.D. 457), Commentary on Hebrews, Chapter 13, in Theodoret of Cyrus, Commentary on the Letters of St. Paul, Volume 2, p. 196 (2001), Robert C. Hill translator.