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]. (ID)
App reference (ID): Book 6, Hadith 24 (ID)
Arabic/English book reference (ID): Book 6, Hadith 868 (ID)