Greeting Non-Muslims and the Prohibition of Taking Initiative in Doing So Riyad as-Salihin 867

Arabic hadith text
وعن أنس رضي الله عنه قال‏:‏ قال رسول الله صلى الله عليه وسلم‏:‏ ‏"‏إذا سلم عليكم أهل الكتاب فقولوا‏:‏ وعليكم” ‏(‏‏(‏متفق عليه‏)‏‏)‏
Translation
Anas (May Allah be pleased with him) reported

Messenger of Allah (ﷺ) said, "When the people of the Book greet you, respond with: 'Wa 'alaikum' (And upon you)".[Al-Bukhari and Muslim].