Adh-Dhariyat 51:25

Ith dakhaloo AAalayhi faqaloosalaman qala salamun qawmun munkaroon

When they entered upon him and said, "[We greet you with] peace." He answered, "[And upon you] peace; [you are] a people unknown."

When they (the angels in human form) entered unto him and said, “We greet you with Salām .” He said, “Salām on you.” (And he said to himself,) “(They are) unknown people.”