וַיֹּאמְר֣וּ אֵׄלָׄ֔יׄוׄ אַיֵּ֖ה שָׂרָ֣ה אִשְׁתֶּ֑ךָ וַיֹּ֖אמֶר הִנֵּ֥ה בָאֹֽהֶל׃
그들이 아브라함에게 이르되 네 아내 사라가 어디 있느냐 대답하되 장막에 있나이다
Rashi
ויאמרו אליו AND THEY SAID UNTO HIM — The letters 'א' י' ו of the word אליו have dots over them (thus distinguishing these letters which form the word meaning “where is he”?). R. Simeon the son of Eleazar said: wherever you find in a particular word or phrase that the letters in ordinary writing are more numerous than those dotted, you should give a special interpretation to those in ordinary writing. Here the dotted letters are more than those in ordinary writing and you, therefore, give an explanation of the dotted letters — that of Sarah also, they asked, איו “where is he (Abraham)”? So we may learn that in his inn a man should enquire of the man (the host) as to his wife’s welfare and of the woman (the hostess) about her husband’s. In Treatise Bava Metzia (87a) it is stated: The ministering angels knew, indeed, where our mother Sarah was but they asked this question in order to call attention to her modesty (retiring disposition) and so to endear her all the more to her husband.) R. José the son of Haninah stated that they enquired where she was in order to send her the wine-cup of blessing (the glass of wine held by him who recites the Grace after meals)
Rashbam
?איה שרה אשתך, even though the angels knew Sarah’s whereabouts they asked, just as G’d did in Genesis 3,9 when He asked Adam about his whereabouts although He knew full well where Adam was. A similar situation is found in Numbers 22,9 when G’d asked Bileam who the men were who had come to spends the night with him. G’d knew perfectly well who they were.
Radak
ויאמרו אליו, there are dots on the letters יו. Such dots can only be explained by our resorting to allegorical interpretations. For instance, our sages quote Rabbi Shimon ben Eleazar as saying that whenever the dot appears to include someone or something not mentioned in the text as written, we pay heed primarily to these dots. When the dots seem to exclude part of the text as written, we stick to the text in our interpretation of the verse. In our case, the dots mean that the angels also enquired from Sarah where to find Avraham. This teaches that a guest is to enquire from the host about the hostess and from the hostess about the host. The sages say further that the angels knew very well where Sarah was at that time, but the question is reported only to draw attention to the modesty of Sarah who was not in evidence, did not allow her curiosity about the nature of the guests to cause her to peek out of her tent. Knowing that she was so modest would endear her even further to her husband. Rabbi Yossi bar Chaninah says that the purpose of the enquiry was to be able to hand her a cup of blessing. [not literally, but a reference to the good news they brought. Ed.]