The Rocky Tract - 15:52 "They came to him and said, "Peace be upon you!"He said: "We are afraid of you"."
In the context of verses 51, 52...60; concerning the guests (angels) of Prophet Abraham:
Prophet Hud/11:69 "When Our messengers brought the good news to Abraham, they said: "Peace be upon you". He said, "Peace be upon you!"and immediately he presented (to them) a roasted calf."
Prophet Hud/11:70 "When he saw that their hands did not reach out to him, he did not like their condition; a fear fell upon him. "Do not be afraid,"they said, "We have been sent to Lot´s people."
Prophet Hud/11:71 When his standing wife laughed, We gave him (Abraham) the glad tidings of Isaac and Jacob after Isaac.
Prophet Hud/11:72 "Woe to me,"she said, "am I to bear a child while I am an old woman and my husband is an old man? This is a very strange thing!"
Prophet Hud/11:73 "They said, "Do you wonder at Allah´s work?"They said, "Allah´s mercy and blessings are upon you, O people of the house. He is the Most Praiseworthy, the Exalted of the Exalted."
Prophet Hud/11:74 When the fear left Abraham and he was given this good news, he began to argue with us about the people of Lot.
Prophet Hud/11:75 Indeed, Abraham was very mild, very sensitive and always turned (to God).
Prophet Hud/11:76 Give it up, Abraham. The command of your Lord has come; they are doomed to an unavoidable torment.

The Scatterers/51:24 Have you heard the news of the guests of Abraham?
The Scatterers/51:25 "They entered his presence and said: "Peace be upon you". He said, "Peace be upon you, strangers!"
The Scatterers/51:26 He turned towards his family and then came with a fat calf.
The Scatterers/51:27 "He set it before them and said, "Will you not eat?"
The Scatterers/51:28 "He felt fear from them. So they said, "Do not be afraid"and gave him the glad tidings of a wise son."
The Scatterers/51:29 "His wife, amazed, struck him on the face and said, "A barren old woman!"
The Scatterers/51:30 "They said, "This is what your Lord has said. He is Wise, Knowing."
The Scatterers/51:31 "(Abraham said): "O messengers, what is your mission?"
The Scatterers/51:32 "They said, "We have been sent to a guilty people."
The Scatterers/51:33 To send upon them stones of clay...
The Scatterers/51:34 Marked by your Lord for the transgressors.
The Scatterers/51:35 Then We drove out whoever therein was of the believers.
The Scatterers/51:36 We did not find therein any Muslim except in a house.
The Scatterers/51:37 We left therein a lesson for those who fear the painful torment.