Genesis 17

The chapter opens with a date that is really an obstacle: And when Abram was ninety years old and nine, the LORD appeared to Abram (v. 1). Ninety-nine. Thirteen silent years have passed since Ishmael was born, and Abram is now well past the age when a man expects his life to change. And the first thing the LORD does is not to issue a command or even repeat the promise; it is to name Himself: I am the Almighty God. The order matters.

Before God says one word about what He will do, He says who He is. Everything in this chapter - a son from a ninety-year-old woman, a nation from one childless man, a covenant that outlasts the centuries - depends entirely on the kind of God who is speaking. So He grounds it all in His own name first: the God who is enough, who has more than enough, at the exact moment when every human reckoning says the season is over.

Then comes the summons: walk before me, and be thou perfect (v. 1). It is a whole way of life pressed into a single sentence. To walk before God is to live the ordinary, daily round of one's life in His presence and under His gaze: a steady, conscious walking that knows it is seen. And be thou perfect carries the sense of whole, complete, sound all the way through - undivided, with nothing held back from God.

It is the call to a single-hearted life, integrity in the old sense of the word: integrated, all of one piece. Notice too that the command rests on the name just spoken. Because God is El Shaddai, the all-sufficient One, the walk He asks for is a life lived before a God who supplies every step of it. The demand and the sufficiency stand together: He asks for a whole heart, and He is the One able to sustain it.

God now states the heart of what He is doing: I will make my covenant between me and thee, and will multiply thee exceedingly (v. 2). A covenant is a solemn, binding pledge - and here the One binding Himself is the stronger party, putting His own name and honour on the line to bless the weaker. My covenant, He calls it; the initiative is entirely His. Abram's response is the only fitting one: Abram fell on his face (v. 3).

He does not negotiate or add conditions; he goes to the ground before the God who is speaking. And from that posture he hears the promise unfold in widening circles: many nations (v. 4), kings coming out of him (v. 6), the covenant reaching past him to thy seed after thee through all their generations (v. 7). What was a private hope for an heir becomes a promise the size of history.

Twice in these verses the promise is called everlasting - an everlasting covenant (v. 7) and the land given for an everlasting possession (v. 8). The Hebrew word behind it, olam, reaches out to the far horizon, into the age itself and beyond what the eye can see. And the covenant carries inside it the warmest words in the whole chapter: to be a God unto thee, and to thy seed after thee… and I will be their God (vv. 7-8).

This is the beating heart of every covenant God makes in Scripture: the gift of God Himself. I will be their God. The land and the offspring are the setting for the real treasure: that the Maker of heaven and earth binds Himself to be the God of this family, generation after generation. The covenant is, at its core, about whose Abraham now is.

God now gives the covenant a token - a sign - and it is unlike any other. It is not an altar to be visited or a feast to be kept once a year. It is set in the body itself: ye shall circumcise the flesh of your foreskin; and it shall be a token of the covenant betwixt me and you (v. 11). The sign falls on the very part of a man by which the next generation comes - which is the whole point.

The covenant promised a line that would not end (vv. 6-7); now the promise is marked on the means by which that line continues. The token is therefore generational by design: every father carries it, every son receives it, and the covenant is literally handed down in the flesh from one age to the next. It is also a sign no one outside could impose and no one could quietly remove. Carried in the body, it went everywhere Abraham went, a constant, private witness that he and his offspring belonged to the God who had bound Himself to them.

The details are exact. The sign is given he that is eight days old (v. 12), and it is not limited to Abraham's blood-descendants: he that is born in the house, or bought with money of any stranger is to receive it too (vv. 12-13). The covenant community is wider than one bloodline - everyone brought into Abraham's household is brought under the sign. Twice more the word everlasting returns: my covenant shall be in your flesh for an everlasting covenant (v. 13).

And then the solemn warning: the uncircumcised man child… that soul shall be cut off from his people; he hath broken my covenant (v. 14). The phrase cut off is sobering, and there is a quiet, severe symmetry in it - the one who refuses the cutting of the sign is himself cut off. To despise the token was to step outside the covenant altogether, to set oneself apart from the people God had pledged Himself to keep.

The sign was grace, but it was grace that asked to be received.

The renaming now reaches Sarai: thou shalt not call her name Sarai, but Sarah shall her name be (v. 15). The two forms are close in sound and meaning - both carry the sense of princess - but the change is not idle. Sarai had been, all her life, the barren wife defined by what she could not do; the very name is bound up with a particular, limited household. Sarah is given a wider promise: I will bless her, and give thee a son also of her… she shall be a mother of nations; kings of people shall be of her (v. 16).

Notice how completely she is drawn into the covenant. The promise is spoken of her - nations from her, kings from her. The blessing is doubled in a single verse (I will bless her… yea, I will bless her) as if to settle every doubt. The God who renamed the man now renames the woman, and lifts her from the long defeat of barrenness into the very centre of the promise.

Abraham's response is startling: Then Abraham fell upon his face, and laughed (v. 17). It is worth pausing over, because the laugh is easy to misread. He does not laugh in scorn or refusal - he is, after all, face-down before God, the posture of worship, not mockery; and the New Testament will hold him up as one who staggered not at the promise of God through unbelief (Rom. 4:20). His laugh is the sound a person makes when a promise is so far past the bounds of the possible that the mind reels: Shall a child be born unto him that is an hundred years old? and shall Sarah, that is ninety years old, bear? It is the laughter of a man holding two things at once - the plain impossibility of it by every human measure, and the sheer presence of the God who has just said it will be so.

And in a touch the Hebrew loves, that very laughter will be sealed into the promised child's name. The boundary of the possible is breaking, and laughter is the only honest sound to make.

Out of that overwhelmed heart comes a plea: O that Ishmael might live before thee! (v. 18). It is a deeply human prayer. Abraham has a son already - a boy of thirteen whom he loves - and his instinct is to ask God to bless the one already in his arms. Could not this be the heir? Could not the promise simply settle on Ishmael? God's answer is firm and tender at once: Sarah thy wife shall bear thee a son indeed; and thou shalt call his name Isaac (v. 19).

The word indeed closes the door on every substitute. The covenant line will run through the son God Himself promises and provides - born by God's own power. The heir is God's gift to give. And in that one word, indeed, the whole logic of grace is hidden: the decisive thing is what God does.

God does not brush Ishmael aside. Abraham's plea was heard: And as for Ishmael, I have heard thee: Behold, I have blessed him, and will make him fruitful… twelve princes shall he beget, and I will make him a great nation (v. 20). The blessing is real and generous - fruitfulness, multiplication, twelve princes, a great nation. Yet God draws a clear line in the very next breath: But my covenant will I establish with Isaac (v. 21).

The two statements must be held together. Ishmael is blessed; Isaac is the covenant heir. The two statements must be held in their proper places: Ishmael is loved, prayed for, and abundantly blessed; the covenant is about how God keeps His word: it runs through the child God promised and provided, the one born by His power. And God even fixes the date: at this set time in the next year (v. 21). The promise that drew laughter is given a calendar.

The impossible now has a deadline.

Then the chapter ends in obedience, landing on a phrase repeated twice for emphasis: in the selfsame day (vv. 23, 26). God left off talking with him and went up from Abraham (v. 22) - and Abraham does not wait, does not deliberate, does not put it off for a more convenient season. The same day the command is given, at ninety-nine years old, he takes Ishmael and every male in his household - sons of the house and servants bought with money alike - and circumcises them all, himself included (vv. 23-27).

The detail is striking: Abraham at ninety-nine and Ishmael at thirteen submit on the very same day, and the whole household enters with them. When Abraham steps into the covenant, his entire world steps in with him. There is no gap here between hearing and doing, no delay between the promise received and the response made. The man who laughed at the impossible obeys it immediately and completely. Faith, in the end, is shown in the knife - in the prompt, costly, whole-hearted doing of what God has said.