Why did God give circumcision to Abraham (Gen 17:9–14)? What is it for? It’s not very useful as a “boundary marker” or “badge of membership”, because under most circumstances people can’t tell whether you’ve been circumcised! Furthermore, lots of other ancient peoples practiced circumcision. Can we discern why circumcision is commanded in the story of Abraham?
(This post is part of a series. See here for an introduction to the series.)
We’ve seen the way that Genesis 12-22 describes two distinct but related covenants. God gives Abraham a two-fold set of promises involving, firstly, nationhood (land and seed, inheritance and heir, Gen 12:1–2c) and, secondly, international blessing (Gen 12:2d–3). Abraham’s faith in the promise of seed (Gen 15:6) is the basis for a covenantal commitment by God to give the land to Abraham (Gen 15:7–21). Abraham’s loyalty (Gen 17:1), displayed in his willingness to trust God even to the point of sacrificing the seed of the promise, is the basis for a covenantal commitment by God to bless all nations through Abraham and his great, numerous seed (Gen 17, Gen 22:15–18). Abraham’s children after him must also follow in the footsteps of Abraham’s faith and loyalty in order for international blessing to be accomplished (Gen 18:18–19). The constantly recurring question in the whole of Genesis-Kings is the question of the identity of the “seed” who will mediate international blessing, especially in the light of the recurring failure of the majority of Abraham’s physical descendants (e.g. 2 Kgs 17:20, “And Yahweh rejected the whole seed of Israel”). The focus narrows down onto a “royal” seed, one from the line of David, for whom God will establish an “everlasting kingdom” (2 Sam 7).
God’s command for Abraham and his descendants to be circumcised occurs in the description of the second of these covenants (Genesis 17).
Circumcision itself is not a major feature in the Old Testament; it is assumed as an obligation for Abraham’s descendants and those in their household (Gen 21:1–4; 34:13–30; Exod 12:48; Lev 12:3; Josh 5:1–9, cf. Judg 14:3, 15:18; 1 Sam 14:6, 17:26, 17:36, 31:4; 2 Sam 1:20; 1 Chr 10:4; Isa 52:1; Ezek 28:10, 31:18, 32:19–32, 44:7–9), required to avoid curse and death (Exod 4:22–26), often internalized (Exod 6:12; Lev 26:40–43; Deut 10:16; Deut 30:5–6; Jer 4:4, 6:10, 9:25–26; Hab 2:16), but seldom explained. Yet Paul deals with circumcision with some frequency and at some length (Rom 2:25–29, 3:1, 3:30, 4:9–12, 15:8; 1 Cor 7:18–19; Gal 2, 5, 6; Eph 2:11; Phil 3:3–5; Col 2:11–13, 3:11, 4:11; Tit 1:10). How is the “covenant” of circumcision in Genesis 17 related to the covenant of international blessing described in the rest of the chapter? Some would see them as two entirely separate covenants. However, it seems best to assume with Hugenberger that בְּרִית in Gen 17:9, 13 is shorthand for a specific obligation (Gen 17:10) or sign (Gen 17:11) within the covenant of Genesis 17.
But is circumcision simply an ethnic “boundary marker” or “badge”, or does it actually signify something? It is not, in fact, particularly useful as a “boundary marker”, for many of Israel’s ANE neighbours also practiced circumcision. Moreover, circumcision is invisible under normal circumstances. But neither does circumcision seem to be a proof or symbol of God’s activity, or a sign to remind God of his obligations (cf. Gen 9:16–17). It seems to be a sign for the sake of the one circumcised. Williamson suggests that circumcision reminds the Israelites to “walk before God and be blameless (תָּמִים, whole)”. Yet it is difficult to see how cutting off a part of one’s body would remind one to “be whole”. Goldingay sees the significance of circumcision in “disciplining of (especially male) procreation” (an interpretation also found in Paul’s contemporary Philo).
The narrative context of Genesis 17 may shed light on this question. Given chapter 16 and 17:17–18, circumcision may be a symbolic means to perpetually restrain Abraham’s desire to achieve God’s purposes through his own effort (i.e. his “flesh”). God commands Abraham and his seed to “cut” the very instrument that Abraham had used to try to fulfil the Genesis 15 promise of seed by begetting Ishmael through Hagar (Chapter 16). Abraham had thought that Ishmael (the result of his own effort) was to be the seed (17:17–18). But God, while promising international blessing through Abraham’s blameless walk (17:1) simultaneously restrains Abraham’s natural inclination to achieve God’s purposes by himself. Thus the purpose of the covenant of circumcision is to remind Abraham that God will make a name for him (Gen 12:2; 17:5); he is not to make a name for himself (cf. Gen 11:4). It also reminds Abraham’s seed of the danger of being “cut off” (כרת) if they should break this covenant (Gen 17:14). Hence circumcision is both a sign and warning of fleshly weakness and a stimulus to faith in the God who can achieve his purposes despite the odds (cf. Rom 4:11–12, 17–19).
 Williamson, Abraham, 182.
 Williamson, Abraham, 253–58.
 E.g. Thomas E. McComiskey, The Covenants of Promise: A Theology of the Old Testament Covenants (Nottingham: IVP, 1985), 146–50; see also Martin Luther, Lectures on Genesis Chapters 15–20 (ed. Jaroslav Pelikan; trans. George V. Schick; LW 3; Saint Louis: Concordia, 1961), 162–63.
 Hugenberger, Marriage, 174; see Williamson, Abraham, 149.
 So N. T. Wright, The Climax of the Covenant (London: T & T Clark, 1991), 3.
 Williamson, Abraham, 176–81.
 Williamson, Abraham, 176–81.
 Williamson, Abraham, 180–81.
 John Goldingay, “The Significance of Circumcision”, Journal for the Study of the Old Testament 88 (2000): 3–18.