Be not forgetful to entertain strangers (τῆς φιλοξενίας μὴ ἐπιλανθάνεσθε)
Lit. be not forgetful of hospitality. Φιλοξενία only here and Rom 12:13. olxx. Φιλόξενος hospitable, 1Ti 3:2; Tit 1:8; 1Pe 4:9. The rendering of Rev. to show love unto strangers, is affected. On the injunction comp. Rom 12:13; 1Ti 3:2; Tit 1:8; 1Pe 4:9, and see Clem. Rom. Ad Corinth. x., xi., xii. The virtue of hospitality is not distinctively Christian. It appears with the very beginnings of history, largely as the result of nomadic conditions. It was peculiarly an Oriental virtue. In the Egyptian Book of the Dead, commendatory judgment is awarded to him who has fed the hungry and clothed the naked. The O.T. abounds in illustrations, and the practice of hospitality among the Arabs and Bedoueen is familiar through the writings of travelers in the East. Great stress was laid on the duty by the Greeks, as appears constantly in Homer and elsewhere. Hospitality was regarded as a religious duty. The stranger was held to be under the special protection of Zeus, who was called ξένιος, the God of the stranger. The Romans regarded any violation of the rites of hospitality as impiety. Cicero says: “It seems to me eminently becoming that the homes of distinguished men should be open to distinguished guests, and that it is an honor to the Republic that foreigners should not lack this kind of liberality in our city” (De Off. ii. 18).
Have entertained angels unawares (ἔλαθόν τινες ξεσίσαντες ἀγγέλους)
The Greek idiom is, “were not apparent as entertaining angels.” The verb ἔλαθον were concealed represents the adverb unawares. For similar instances see Mar 14:8; Act 12:16; Aristoph. Wasps, 517; Hdt. i. 44; Hom. Il. xiii. 273. Ξενίζειν to receive as a guest, mostly in Acts. In lxx only in the apocryphal books. In later Greek, to surprise with a novelty; passive, to be surprised or shocked. So 1Pe 4:4, 1Pe 4:12; comp. 2 Ep. of Clem. of Rome (so called), xvii.: To be a stranger or to be strange, once in N.T., Act 17:20. Ξενισμός amazement, perplexity, not in N.T. lxx, Pro 15:17. Comp. Ignatius, Eph. xix. The allusion to the unconscious entertainment of angels is probably to Genesis 18, 19, but the idea was familiar in Greek literature. The Greeks thought that any stranger might be a God in disguise. See Hom. Od. i. 96 ff.; iii. 329-370; xvii. 485. Comp. also the beautiful story of Baucis and Philemon as related by Ovid (Metam. viii. 626-724). The thought appears in our Lord's words, Mat 25:34-46.