رِيَاضُ الصَّالِحِينَ
Riyad as-Salihin 868
The Book of Greetings
Greeting Non-Muslims and the Prohibition of Taking Initiative in Doing So
وَعَنْ أسامة رَضِيَ اللَّه عَنْهُ أَنَّ النَّبِيَّ صَلَّى اللَّه عَلَيْهِ وَسَلَّمَ مر على مَجْلِسٍ فِيهِ أَخْلاَطٌ مِنَ الْمُسْلِمِينَ وَالْمُشْرِكِينَ -عَبَدَةِ الأَوْثَانِ وَالْيَهُودِ- فَسَلَّمَ عَلَيْهِمُ النَّبِيُّ صَلَّى اللَّه عَلَيْهِ وَسَلَّمَ" ((مُتَّفَقٌ عَلَيْهِ)).
Usamah bin Zaid (May Allah be pleased with him) reported: The Prophet (ﷺ) passed by a mixed company of people which included Muslims, polytheists and Jews, and he gave them the greeting (i.e., saying As- Salamu 'Alaikum). [Al-Bukhari and Muslim].
Riyad as-Salihin, 868