A man asked the Messenger of Allah ﷺ, "Which aspect of Islam is best?"He replied, "That you feed others and offer the greeting of peace to those you know and those you do not know."
أن رجلا سأل رسول الله ﷺ: أي الإسلام خير؟ قال: تطعم الطعام، وتقرأ السلام على من عرفت ومن لم تعرف.
Bukhari reported it in the Book of Seeking Permission (6236), and Muslim in the Book of Faith (39), both through routes from Layth, from Yazid bin Abu Habib, from Abu Khayr, from Abdullah bin Amr, who narrated it.