Аз-Зарият 51:25

Comforting the Messenger of Allah

فَقَالُوا سَلَامًا قَالَ سَلَامٌ ("We greet you with salam." He said, "Salam on you." 51:25). The angels greeted him with salaman in the accusative case, whereas Holy Prophet Ibrahim (علیہ السلام) responded to the greeting in the -nominative case thus: salamun. The nominative case in Arabic is a nominal sentence which carries the sense of greater strength, continuity and persistence. The Qur'anic injunction is that 'when you are greeted with a salutation, greet one better than it...', so Holy Prophet Ibrahim (علیہ السلام) the Friend of Allah chose a better reply, implementing Allah's command: reciprocating the greeting with the term salaman is stronger than the greeting using the term salaman.

قَوْمٌ مُّنكَرُ‌ونَ ("[ They are ] unknown people."... 51:25). The word munkar, the letter [م m ] carrying dammah and the letter [ ک k ] carrying fath means "unknown". As sin or sinful work is unknown in Islam, it is also referred to as munkar. The angels came to Holy Prophet Ibrahim (علیہ السلام) in the image of handsome young wonderfully graceful men; therefore he could not recognize them. He thought to himself that these are strangers and said to himself 'They are unknown to me'. Or it is possible that he might have mentioned this to the guests in the form of a question and the purpose might have been to find out who they were.