Hadith 4629
وَعَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو: أَنَّ رَجُلًا سَأَلَ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: أَيُّ الْإِسْلَامِ خَيْرٌ؟ قَالَ: «تُطْعِمُ الطَّعَامَ وَتَقْرَأُ السَّلَامَ عَلَى مَنْ عَرَفْتَ وَمَنْ لم تعرف»
It is narrated from Abdullah bin Amr (may Allah be pleased with him) that a man asked the Messenger of Allah (peace and blessings be upon him): "Which (manners) of Islam are the best?" He replied: "(That) you feed (others), and you greet with peace both those whom you know and those whom you do not know." Agreed upon.