A Jewish man passed by the Messenger of Allah ﷺ and said, "Death be upon you."The Messenger of Allah ﷺ replied, "And upon you."Then the Messenger of Allah ﷺ asked, "Do you know what he said? He said, 'Death be upon you.'"They said, "Messenger of Allah, shall we not kill him?"He replied, "No. When the People of the Book greet you, say, 'And upon you.'"
مر يهودي برسول الله ﷺ فقال: السام عليك، فقال رسول الله ﷺ: وعليك فقال رسول الله ﷺ: أتدرون ما يقول؟ قال: السام عليك قالوا: يا رسول الله، ألا نقتله؟ قال: لا، إذا سلم عليكم أهل الكتاب، فقولوا: وعليكم.
Bukhari narrated it in "The Retraction of Apostates" (6926), from Muhammad bin Muqatil Abu Hasan, who said, Abdullah told us, Shubah told us, from Hisham bin Zayd bin Anas bin Malik, who said, I heard Anas bin Malik say, then he related it.