Its permanence is emphasized by the _tense_ of the verb relating to it. The Greek _perfect_ describes settled facts, actions or events that carry with them finality. Accordingly we read in vv. 15 and 17 of "a ratified covenant"--one that _stands_ ratified. In ver. 18, "God hath granted it to Abraham"--a grace never to be recalled. Again (ver. 19), "the seed to whom the promise hath been made"--once for all. A perfect participle is used of the Law in ver. 17 (γεγονώς), for it is a fact of abiding significance that it was so much later than the Promise; and in ver. 24, "the Law hath been our tutor,"--its work in that respect is an enduring benefit. Otherwise, the verbs relating to Mosaism in this context are past in tense, describing what is now matter of history, a course of events that has come and gone. Meanwhile the Promise remains, an immovable certainty, a settlement never to be disturbed. The emphatic position of ὁ Θεός (ver. 18), at the very end of the paragraph, serves to heighten this effect. "It is _God_ that hath bestowed this grace on Abraham." There is a challenge in the word, as though Paul asked, "Who shall make it void?"[93] [93] Comp. Rom. viii. 33, 34; Acts xi. 17; 2 Cor. i. 21, for a similar emphasis. Paul's chronology in ver. 17 has been called in question. We are not much concerned to defend it. Whether Abraham preceded Moses by four hundred and thirty years, as the Septuagint and the Samaritan text of Exod. xii. 40, 41 affirm, and as Paul's contemporaries commonly supposed; or whether, as it stands in the Hebrew text of Exodus, this was the length of time covered by the sojourn in Egypt, so that the entire period would be about half as long again, is a problem that Old Testament historians must settle for themselves; it need not trouble the reader of Paul. The shorter period is amply sufficient for his purpose. If any one had said, "No, Paul; you are mistaken. It was six hundred and thirty, not four hundred and thirty years from Abraham to Moses;" he would have accepted the correction with the greatest goodwill. He might have replied, "So much the better for my argument."[94] It is possible to "strain out" the "gnats" of Biblical criticism, and yet to swallow huge "camels" of improbability. [94] We gain nothing, and we may lose much, in "trying to settle questions of Old Testament historical criticism by casual allusions in the New Testament." (See Mr. Beet's sensible observations, in his Commentary _ad loc._) II. Ver. 16 remains for our consideration. In proving the steadfastness of the covenant with Abraham, the Apostle at the same time directs our attention to _the Person designated by it_, to whom its fulfilment was guaranteed. "To Abraham were the promises spoken, and to his seed--'to thy seed,' which is Christ."