Paul has just told the Galatians what they are: ἐπαγγελίας τέκνα, children of promise, on the pattern of Isaac (v. 28). Verse 29 immediately attaches the cost. The ἀλλά is not a correction but a hard turn: being the Isaac-child does not mean being unopposed; it means being the one who gets hounded.

Three features carry the verse:

1. A then/now correlation (ὥσπερ … οὕτως καὶ νῦν) that Paul leaves grammatically unfinished. There is no verb in the second half. He names the ancient pattern and simply says “so also now,” letting the Galatians supply their own situation.
2. A paired prepositional formula, κατὰ σάρκα / κατὰ πνεῦμα, which reworks the κατὰ σάρκα / διʼ ἐπαγγελίας pair of v. 23. Promise-birth has become Spirit-birth — the same identification Paul made in vv. 4-6, where the sending of the Son and the sending of the Spirit are two halves of one act.
3. An imperfect verb, ἐδίωκε: sustained, repeated harassment, not one recorded outburst.

The exegetical pressure point is that Genesis 21 never actually says Ishmael persecuted Isaac. It says he laughed (מְצַחֵק, Gen 21:9 — a pun on Isaac’s own name). Paul is reading the text through a Jewish interpretive tradition that had already filled that verb with hostility. That is not a flaw to be excused; it is data about how Paul reads Scripture, and it needs to be shown rather than smoothed.

The correlative pair ὥσπερ … οὕτως is standard Koine for a strict analogy (Rom 5:19; 11:30-31). What is not standard is that the second limb has no verb. Greek can do this — ellipsis of a verb recoverable from the first limb is ordinary — but the effect here is rhetorical, not merely economical.

What exactly is elided is genuinely open:

• οὕτως καὶ νῦν [διώκει] — “so now also he persecutes,” continuing the singular subject as a type;
• οὕτως καὶ νῦν [γίνεται] — “so it happens now as well,” generalizing to a state of affairs;
• or the ellipsis simply stands, and Paul stops mid-analogy on purpose.

The third is attractive. Paul has not yet said who the persecutors are. Verse 30 will quote Sarah’s demand that the slave woman and her son be thrown out, but even there the identification is left to the reader. Chrysostom, commenting on the passage, reads the point as consolation: the opposition is itself evidence that the Galatians stand in Isaac’s place.

The καί is adjunctive (“also”), not connective. It adds the present instance to the ancient one; deleting it — as some smoother English does — removes the claim that the two belong to one series.

Both nouns are anarthrous and both prepositions are κατά + accusative in the norm/mode sense already fixed in the glossary: the standard by which the birth is characterized, not the agent by whom it was effected. “Born of the flesh” tips toward material source; “by way of the flesh” or “according to flesh” keeps the standard sense.

The substitution is the theological move. In v. 23 the pair was κατὰ σάρκα / διʼ ἐπαγγελίας (promise, with διά of means). Here the second member becomes κατὰ πνεῦμα. Paul has silently equated promise-birth with Spirit-birth, which is legitimate within his own argument because 4:6 has already made the Spirit the instrument by which sonship is realized, and 3:14 makes the promise’s content the Spirit itself.

On σάρξ: the standing corpus policy keeps one English gloss, “flesh,” across the neutral and polemical uses. Here it is neither morally neutral (as at Phil 1:22) nor a name for sinful impulse (as in Rom 8). It denotes ordinary human generative capacity considered as a basis for standing — Abraham and Hagar producing an heir by available means. The pejorative charge comes from the antithesis, not from the lexeme.

On πνεῦμα: capitalized here, against the lower-case option, because Galatians 3-4 has been running on the Holy Spirit as the mark of sonship (3:2, 3, 5, 14; 4:6). A reading that takes πνεῦμα as “spiritual manner” in the abstract is grammatically available but has nothing in the chapter to support it.

Aorist passive participle. The voice matters and should not be flattened to an active English construction (“the one who was born by the flesh” is fine; “the one the flesh produced” is not). Ishmael is presented as the object of his own generation — a thing done to him, not by him. Paul is not blaming Ishmael for his origin; he is classifying it.

Note the tense contrast across the verse: the aorist participle gives the completed fact of birth, the imperfect main verb gives the ongoing consequence. Cf. v. 23, where the same verb stands in the perfect (γεγέννηται) of Ishmael — the settled standing state — over against this aorist, which is simply narrative background.

The object phrase is τὸν κατὰ πνεῦμα — article, prepositional phrase, and nothing else. No participle is expressed. Greek permits the article to govern a bare prepositional phrase attributively (already fixed in the glossary at τὴν ἐν νόμῳ, Phil 3:6), so the construction is unremarkable in itself; but here the reader must carry γεννηθέντα over from the first limb.

The economy is deliberate and worth preserving. English needs a supplied noun: the literal tier brackets it (“the [one] according to Spirit”), and smooth registers may write “the son born by way of the Spirit,” with the addition noted. What must not happen is a rendering that supplies a different verb — “the one who lives by the Spirit,” for instance — which would convert a statement about origin into a statement about conduct.

The glossary already splits διώκω by object: “persecute” with a hostile personal object, “pursue” with a goal-object. Phil 3:6 (persecuting the assembly) against Phil 3:12, 14 (pursuing the prize) is the type case, and this verse falls squarely on the hostile side.

The imperfect is the exegetically loaded feature. It is durative or iterative: a settled campaign of harassment, not a single act. English “persecuted” is a punctiliar-sounding past and loses this; the study and literal tiers should read “was persecuting” or “kept persecuting.” The point matters because it is the imperfect, more than the lexeme, that carries Paul’s claim about a pattern — which is what licenses the οὕτως καὶ νῦν.

On the form: NA28 prints ἐδίωκε without the final nu. Movable nu before a consonant is optional and the manuscripts vary freely; nothing exegetical rides on it.

The Hebrew of Gen 21:9 (BHS, Leningrad Codex) reads that Sarah saw the son of Hagar the Egyptian מְצַחֵק — a Piel participle of צחק, “laughing, playing, making sport.” It is a pun: Isaac’s name is יִצְחָק, from the same root. The son of the slave woman was “Isaac-ing.”

The LXX renders παίζοντα μετὰ Ισαακ τοῦ υἱοῦ αὐτῆς — “playing with Isaac her son.” The LXX plus (μετὰ Ισαακ, absent from MT) actually softens the scene by naming a playmate. Neither text has a word for persecution.

So where does Paul’s ἐδίωκε come from?

The Piel of צחק is not innocent everywhere: at Gen 39:14 it carries a sense of mocking or sexual sport, and at Exod 32:6 it describes the revelry at the golden calf. Jewish interpreters expanded the ambiguity aggressively, reading Gen 21:9 as mockery, quarrel over inheritance, or worse. Paul is drawing on that reading tradition, not inventing it, and the tradition has a foothold in the Hebrew verb’s own range.

One further textual datum: Sarah’s demand in Gen 21:10, which Paul quotes verbatim in the next verse, gives the reason for expulsion as inheritance — “he shall not inherit with my son Isaac.” The narrative itself frames Ishmael as a threat to Isaac’s standing, which is exactly the frame Paul needs.

Verses 29, 30, and 31 all open with ἀλλά, and the particle does different work each time. Here it is the strong contrastive already fixed in the glossary: the clause cuts against the reassurance of v. 28 rather than extending it. At v. 30 the ἀλλά introduces a rhetorical question turning to Scripture’s verdict. At v. 31 it stands inside the οὐκ … ἀλλά antithesis.

Per §10, the connective is rendered, not dropped, and clause-initial position is kept. Because the same particle recurs three times in three verses, English should use “but” at each occurrence rather than varying to “yet” or “however” for style — the repetition is Paul’s, and the reader should be able to see it.

The verse is textually stable in substance. NA28 records no variant that changes the sense, and it is not among the passages Metzger’s committee found worth discussing.

Two minor spelling-level matters:

• ἐδίωκε / ἐδίωκεν — movable nu, freely variable in the manuscripts, no consequence.
• ἀλλʼ / ἀλλά — elision before ὥσπερ is an editorial orthographic decision, not a manuscript variant of substance.

The only reading of any interest is the occasional Byzantine addition of a verb in the final clause, filling out οὕτως καὶ νῦν. This is exactly the scribal instinct that modern translations reproduce when they insert “it is” unbracketed: a shorter, harder text being smoothed. The critical text’s verbless clause is original, and the ellipsis should survive into English.

Paul has assigned the roles: Hagar/Sinai/present Jerusalem/slavery on one side, Sarah/promise/Jerusalem above/freedom on the other (vv. 24-26). Verse 29 activates that assignment historically — the slave-line has always harried the promise-line, and does so still.

Two things need saying plainly, per §5.

First, Paul does not name the present persecutors. The context of the letter points to the agitators pressing circumcision on Gentile believers (cf. 5:11, 6:12), and it is worth noting that in 6:12 Paul says those agitators are themselves acting to avoid being persecuted. The verse does not license a general reading of Jewish people as Ishmael. Paul is a Jew arguing with other Jews about who inherits Abraham, and 4:29’s ὁ κατὰ σάρκα γεννηθείς is a functional category within that argument, not an ethnic verdict. The rendering leaves the referent unspecified because Paul left it unspecified.

Second, the verse is consolation as much as accusation. Opposition is presented as the mark of the promise-line, not evidence against it — the same logic as Phil 1:28-29, where suffering for Christ is a granted thing and a proof. The Galatians who are being told they lack something are being told instead that what they are experiencing belongs to what they are.