Finding fault with them (mempomeno autou). Present middle participle of mempomai (cf. amempto), old verb, in N.T. only here and Romans 9:19 . The covenant was all right, but the Jews failed to keep it. Hence God made a new one of grace in place of law. Why do marriage covenants so often fail to hold? The author quotes in verses Romans 8-12 ; Jeremiah 31:31-34 (in LXX Jeremiah 31:31-34 ) in full which calls for little explanation or application to prove his point (verse Hebrews 8:13 ). I will make (suntelesw). Future active of suntelew, old compound verb to accomplish as in Mark 13:4 ; Romans 9:28 . A new covenant (diaqhkhn kainhn). In Hebrews 12:24 we have diaqhkh nea, but kainh in 1 Corinthians 11:25 . Kaino is fresh, on new lines as opposed to the old (palaio) as in 2 Corinthians 3:62 Corinthians 3:14 ; neo is young or not yet old.