Be not forgetful to entertain strangers: for thereby some have entertained angels unawares.
Two manifestations of "brotherly love" - hospitality and care for those in bonds.
Be not forgetful. They all recognized the duty, but might forget to act on it (Hebrews 12:3; Hebrews 12:7; Hebrews 12:16). The enemies of Christianity themselves noticed this virtue among Christians (Julian, 'Ep.' 49),
Entertained angels unawares - Abraham and Lot (Genesis 18:2; Genesis 19:1). To obviate the natural distrust of strangers, Paul says an unknown guest may be better than he looks: he may be found as much a messenger of God for good as the angels (whose name means messenger) are; nay more, if a Christian, he represents Christ. There is a play on the same Greek х epilanthanesthe (G1950) ... elathon (G2990)]: let not the duty of hospitality to strangers escape you; for, by entertaining, strangers, it has escaped the entertainers that they were entertaining angels. Not unconscious of the duty, they have unconsciously brought on themselves the blessing.