And I will establish my covenant between me and thee and thy seed after thee in their generations for an everlasting covenant, to be a God unto thee, and to thy seed after thee.
Ver. 7. For an everlasting covenant.] Circumcision, the outward sign of it, was temporary, and changeable into baptism; but the covenant of grace, thereby then, and by baptism now, sealed up unto us, is eternal; being established and ratified. by the death of the Testator, "by the blood of the Arch-shepherd". Heb 13:20 Here it must be considered a that there is a twofold covenant: 1. Single; such as God makes with children, when baptized; viz., if you will repent, believe, and walk with me, ye shall be saved. Now, if they break the condition, God is freed, he it not bound any further. 2. Double; such as God makes with his elect only; and that is to perform both parts, sc., if you will believe, repent, obey, ye shall be saved: and further, I will give you a new heart, so that you shall repent, believe, &c., and be saved. Thus God undertakes for both parts, and so it becomes an everlasting covenant, such as hath the "sure" or unfailable "mercies of David" b Isa 55:3 And here those, that are in double covenant with God, are fitly compared to them that are gone in at a church door: some are farther in than others, but yet all are in. So, though the weak in faith be not so forward, yet they may be in, though not so far in.
And to thy seed after thee.] See Trapp on " Gen 17:8 "
a Dr Preston Of God's Attributes
b Tα οσια του Dαβιδ