Abu Huraira reported: The Messenger of Allah, peace and blessings be upon him, said, “Whoever believes in Allah and the Last Day, let him speak goodness or be silent. Whoever believes in Allah and the Last Day, let him honor his neighbor. Whoever believes in Allah and the Last Day, let him honor his guest.”

Source: Sahih Muslim 47

Grade: Sahih (authentic) according to Muslim

عَنْ أَبِي هُرَيْرَةَ عَنْ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ مَنْ كَانَ يُؤْمِنُ بِاللَّهِ وَالْيَوْمِ الْآخِرِ فَلْيَقُلْ خَيْرًا أَوْ لِيَصْمُتْ وَمَنْ كَانَ يُؤْمِنُ بِاللَّهِ وَالْيَوْمِ الْآخِرِ فَلْيُكْرِمْ جَارَهُ وَمَنْ كَانَ يُؤْمِنُ بِاللَّهِ وَالْيَوْمِ الْآخِرِ فَلْيُكْرِمْ ضَيْفَهُ

47 صحيح مسلم كِتَاب الْإِيمَانِ باب الْحَثِّ عَلَى إِكْرَامِ الْجَارِ وَالضَّيْفِ وَلُزُومِ الصَّمْتِ إِلَّا عَنْ الْخَيْرِ

http://dailyhadith.abuaminaelias.com/2010/09/22/let-him-speak-goodness-let-him-honor-his-neighbor-and-guest/