Be not forgetful to entertain strangers: for thereby some have entertained angels unawares.
a. ASV: Forget not to show love unto strangers: for thereby some have entertained angels unawares.
b. YLT: Of the hospitality be not forgetful, for through this unawares certain did entertain messengers;
d. Amplified Bible Classic: Do not forget or neglect or refuse to extend hospitality to strangers [in the brotherhood—being friendly, cordial, and gracious, sharing the comforts of your home and doing your part generously], for through it some have entertained angels without knowing it.
1. “Be not forgetful to entertain strangers…”
a. [Strong: 3588 ho ho, including the feminine he hay, and the neuter to to in all their inflections; the definite article; the (sometimes to be supplied, at others omitted, in English idiom):--the, this, that, one, he, she, it, etc.] [Thayer: [Tes] ὁ, ἡ, τό, originally τος, τῇ, τό (as is evident from the forms τοι, ται for οἱ, αἱ in Homer and the Ionic writings), corresponds to our definite article the (German der, die, das), which is properly a demonstrative pronoun, which we see in its full force in Homer, and of which we find certain indubitable traces also in all kinds of Greek prose, and hence also in the N. T.]
b. [Be] not [Strong: 3361 mḗ, may; a primary particle of qualified negation (whereas G3756 expresses an absolute denial); (adverb) not, (conjunction) lest; also (as an interrogative implying a negative answer (whereas G3756 expects an affirmative one)) whether:—any but (that), × forbear, + God forbid, + lack, lest, neither, never, no (X wise in), none, nor, (can-)not, nothing, that not, un(-taken), without. Often used in compounds in substantially the same relations.]
c. forgetful [Strong: 1950 epilanthánomai, ep-ee-lan-than'-om-ahee; middle voice from G1909 and G2990; to lose out of mind; by implication, to neglect:—(be) forget(-ful of).]
d. [to] entertain strangers [Strong: 5381 philonexía, fil-on-ex-ee'-ah; from G5382; hospitableness:—entertain stranger, hospitality.]
2. “...for thereby some have entertained angels unawares.”
a. for [Strong: 1063 gár, gar; a primary particle; properly, assigning a reason (used in argument, explanation or intensification; often with other particles):—and, as, because (that), but, even, for, indeed, no doubt, seeing, then, therefore, verily, what, why, yet.]
b. thereby [Strong: 1223 diá, dee-ah'; a primary preposition denoting the channel of an act; through (in very wide applications, local, causal, or occasional):—after, always, among, at, to avoid, because of (that), briefly, by, for (cause) … fore, from, in, by occasion of, of, by reason of, for sake, that, thereby, therefore, × though, through(-out), to, wherefore, with (-in).]
c. [Strong: taútēi, tow'-tay; dative case, accusative case and genitive case respectively of the feminine singular of G3778; (towards or of) this:—her, + hereof, it, that, +thereby, the (same), this (same).]
d. some [Strong: 5100 tìs, tis; an enclitic indefinite pronoun; some or any person or object:—a (kind of), any (man, thing, thing at all), certain (thing), divers, he (every) man, one (X thing), ought, + partly, some (man, -body, - thing, -what), (+ that no-)thing, what(-soever), ×wherewith, whom(-soever), whose(-soever).]
e. [have] entertained [Strong: xenízō, xen-id'-zo; from G3581; to be a host (passively, a guest); by implication, be (make, appear) strange:—entertain, lodge, (think it) strange.]
f. angels [Strong: 32 ággelos, ang'-el-os; from ἀγγέλλω aggéllō (probably derived from G71; compare G34) (to bring tidings); a messenger; especially an "angel"; by implication, a pastor:—angel, messenger.]
g. unawares [Strong: 2990 lanthánō, lan-than'-o; a prolonged form of a primary verb, which is used only as an alternate in certain tenses; to lie hid (literally or figuratively); often used adverbially, unwittingly:—be hid, be ignorant of, unawares.]
1). The only example that scholars give is the incident with Abraham in Genesis 18 and Lot in Genesis 19. In the case of Abraham I believe that Abraham knew it was the LORD God immediately because of previous meetings (Genesis 12:7; Genesis 17:1), but whether he knew the two persons with him were angels was probably revealed to him before the end of the meeting, at least in my thoughts. Concerning Lot, I think that eventually even he realized these were angels, again these are my thoughts.