In the following article an attempt is made to trace the part which the Greek ??????? plays in the teaching of the Epistle to the Hebrews. We leave the Greek word untranslated, because it is in part with the problem of its proper translation that we are concerned and it appears best not to prejudice the question. We notice first of all that Hebrews is the only New Testament document in which the concept and the term diatheke appear with any degree of prominence. In the teaching of our Lord we meet with the idea only once, in the institution of the Supper. More frequently it occurs with Paul, in Romans (9:4; 11:27), 2 Corinthians (3:6, 14), Galatians (3:15, 17; 4:24), Ephesians (2:12), altogether nine times in six contexts. In Luke’s writings we find it, apart from the institution of the Supper, once in the Gospel (1:72), and twice in the Acts (3:25; 7:8). Once also it is met with in the Revelation of St. John (11:19). This makes sixteen instances of its occurrence outside of Hebrews. Over against this stand seventeen occurrences in Hebrews alone. In other words in this single Epistle the conception is more frequent than in all the rest of the New Testament writings put together.