إِذْ دَخَلُوا عَلَيْهِ فَقَالُوا سَلَمًاقَالَ سَلَامٌWhen they came in to him and said:"Salaman!"He answered:"Salamun." وَإِذَا حُيِّيتُم بِتَحِيَّةٍ فَحَيُّواْ بِأَحْسَنَ مِنْهَأ أَوْ رُدُّوهَأWhen you are greeted with a greeting, greet in return with what is better than it, or return it equally. (4:86)So the Friend of Allah chose a better reply in return for their greeting, implementing Allah's command:Reciprocating the greeting with the term Salamun is stronger than the greeting using the term Salaman.The three angels; Jibril, Mika'il and Israfil came to Ibrahim in the image of handsome young wonderfully graceful men. This is why Ibrahim said,قَوْمٌ مُّنكَرُونَYou are a people unknown to me.Allah the Exalted said