Acts 21:24

These take

(τουτους παραλαβων). Second aorist active participle of παραλαμβανω. Taking these alone.Purify thyself with them

(αγνισθητ συν αυτοις). First aorist passive imperative of αγνιζω, old verb to purify, to make pure (αγνος). See the active voice in James 4:8; 1 Peter 1:22; 1 John 3:3. It is possible to see the full passive force here, "Be purified." But a number of aorist passives in the Koine supplant the aorist middle forms and preserve the force of the middle (Robertson, Grammar, p. 819). That is possible here. Hence, "Purify thyself" is allowable. The word occurs in Numbers 6:1 for taking the Nazarite vow. The point is that Paul takes the vow with them. Note αγνισμου in verse Acts 21:26.Be at charges for them

(δαπανησον επ' αυτοις). First aorist active imperative of old verb δαπαναω, to incur expense, expend. Spend (money) upon (επ') them. Ramsay (St. Paul the Traveller, etc., p. 310) argues that Paul had use of considerable money at this period, perhaps from his father's estate. The charges for five men would be considerable. "A poor man would not have been treated with the respect paid him at Caesarea, on the voyage, and at Rome" (Furneaux).That they may shave their heads

(ινα ξυρησοντα την κεφαλην). Note την κεφαλην, the head (singular). Future middle indicative of ξυραω, late form for the old ξυρεω, to shave, middle to shave oneself or (causative) to get oneself shaved. This use of ινα with the future indicative is like the classic οπως with the future indicative and is common in the N.T. as in the Koine (Robertson, Grammar, p. 984).And all shall know

(κα γνωσοντα). This future middle indicative of γινωσκω (cf. ακουσοντα in verse Acts 21:22) may be independent of ινα or dependent on it like ξυρησοντα, though some MSS. (H L P) have γνωσιν (second aorist subjunctive, clearly dependent on ινα).Of which

(ων). Genitive plural of the relative α (accusative) object of the perfect passive verb κατηχηντα (cf. verse Acts 21:21 κατηχηθησαν) attracted into the case of the omitted antecedent τουτων. The instruction still in effect.But that thou thyself walkest orderly

(αλλα στοιχεις κα αυτος). Στοιχεις is an old verb to go in a row (from στοιχος, row, rank, series), to walk in a line or by rule. In the N.T. only here and Galatians 5:25; Romans 4:12; Philippians 3:16. The rule is the law and Paul was not a sidestepper. The idea of the verb is made plain by the participle φυλασσων τον νομον (keeping or observing the law).