At this point, where the discussion opens out into its larger proportions, we observe that the sharp tone of personal feeling with which the chapter commenced has disappeared. In ver. 15 the writer drops into a conciliatory key. He seems to forget the wounded Apostle in the theologian and instructor in Christ. "Brethren," he says, "I speak in human fashion--I put this matter in a way that every one will understand." He lifts himself above the Galatian quarrel, and from the height of his argument addresses himself to the common intelligence of mankind.
But is it _covenant_, or _testament_, that the Apostle intends here? "I speak after the manner of men," he continues; "if the case were that of a man's =diathêkê=, once ratified, no one would set it aside, or add to it." The presumption is that the word is employed in its accepted, every-day significance. And that unquestionably was "testament." It would never occur to an ordinary Greek reader to interpret the expression otherwise. Philo and Josephus, the representatives of contemporary Hellenistic usage, read this term, in the Old Testament, with the connotation of =diathêkê= in current Greek.[90] The context of this passage is in harmony with their usage. The "covenant" of ver. 15 corresponds to "the blessing of Abraham," and "the promise of the Spirit" in the two preceding verses. Again in ver. 17, "promise" and "covenant" are synonymous. Now a "covenant of promise" amounts to a "testament." It is the _prospective_ nature of the covenant, the bond which it creates between Abraham and the Gentiles, which the Apostle has been insisting on ever since ver. 6. It belongs "to Abraham and to his seed"; it comes by way of "gift" and "grace" (vv. 18, 22); it invests those taking part in it with "sonship" and rights of "inheritance" (vv. 18, 26, 29, etc.) These ideas cluster round the thought of _a testament_; they are not inherent in _covenant_, strictly considered. Even in the Old Testament this latter designation fails to convey all that belongs to the Divine engagements there recorded. In a covenant the two parties are conceived as equals in point of law, binding themselves by a compact that bears on each alike. Here it is not so. The disposition of affairs is made by God, who in the sovereignty of His grace "hath granted it to Abraham." It was surely a reverent sense of this difference which dictated to the men of the Septuagint the use of =diathêkê= rather than =synthêkê=, the ordinary term for _covenant_ or _compact_, in their rendering of the Hebrew _berith_.