It may also indicate that they aimed to inform Abraham of...

It may also indicate that they aimed to inform Abraham of their mission as to afflicting the people of Lot (as) with torment and apprise him of his safety and that of his followers. Replying them by saying: “Peace be upon you” he noticed that he did not know them, since he thought that they were human beings and it was his habit to show hospitality to his company. The blessed Verse 26 says that Abraham (as) went to Sarah and had a fattened calf roasted and brought it to his guests.

Noticing that the guests who appeared like human beings to him refrain from eating, he inquired with surprise: “Will you not eat?” Since they were unknown to him and besides they declined his offer to partake of the food, he was afraid of them lest they might be his enemies suspecting some malintention against him. Thus, the angels said unto him: “Fear not.

Then his wife [hearing the glad tidings of a son] came forward with a loud voice: She smote her face and said: “[How] a barren old woman [may conceive a child]!” 30. They [the angels] said [unto him]: “Thus says your Lord. Indeed, He is the All-Wise, the Omniscient.” The Arabic word awjas (“apprehensive, entertaining fear, having presentiments”) derives from w-j-s (“be apprehensive, have presentiments, be seized by fear”).

The Arabic noun Khiyfa (“fear, dread”) derives from the root kh-’-f (“fear, dread”) and its nunnation (tanwin) indicates diversification (tanwi‘) connoting that Abraham was seized by a kind of fear. The blessed Verse is saying that the angels introduced themselves to Abraham saying that they were not human beings in need of partaking food, but they were angels sent on a mission by God Almighty to inform him of a son who would be quite knowledgeable and wise.

The son mentioned herein may refer to Ishmael (Isma‘il) born to Hagar (Hajar). The following blessed Verse indicates that the son mentioned in the blessed Verse 28 was Isaac (Ishaq) born to Sarah (Sara).