Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
quran:51:25 –

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

When (idh is an adverbial qualifier of hadīthu dayfi, ‘the story of the guests’) they entered upon him and said, ‘Peace!’ — in other words ˹they said˺ these very words. He said, ‘Peace!’ — ˹also˺ these very words — ˹These are˺ an unfamiliar folk, whom we do not know — he said this to himself (qawmun munkarūna is the predicate of an implicit subject such as hā’ūlā’i, ‘these are’).
القرآن:٥١:٢٥ –

إِذْ دَخَلُوا عَلَيْهِ فَقَالُوا سَلَامًا ۖ قَالَ سَلَامٌ قَوْمٌ مُنْكَرُونَ  

{إذ} ظرف لحديث ضيف {دخلوا عليه فقالوا سلاما} أي هذا اللفظ {قال سلام} أي هذا اللفظ {قوم منكرون} لا نعرفهم قال ذلك في نفسه وهو خبر مبتدأ مقدر أي هؤلاء.

See similar narrations below:

Collected by Qurʾān
quran:15:52 –

When they entered upon him and said, "Peace." ˹Abraham˺ said, "Indeed, we are fearful of you."  

˹how˺ when they entered unto him, and said, ‘Peace!’, that is, ˹they said˺ this very word (salām). He, Abraham, said, after having offered them food which they did not eat: ‘Lo! we are afraid of you’.
القرآن:١٥:٥٢ –

إِذْ دَخَلُوا عَلَيْهِ فَقَالُوا سَلَامًا قَالَ إِنَّا مِنْكُمْ وَجِلُونَ  

{إذ دخلوا عليه فقالوا سلاما} أي هذا اللفظ {قال} إبراهيم لما عرض عليم الأكل فلم يأكلوا {إنا منكم وجلون} خائفون.