وَعَن ابْن مَسْعُود قَالَ: قَالَ رجل للنَّبِي اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: يَا رَسُولَ اللَّهِ كَيْفَ لِي أَنْ أَعْلَمَ إِذَا أَحْسَنْتُ أَوْ إِذَا أَسَأْتُ؟ فَقَالَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: إِذَا سَمِعْتَ جِيرَانَكَ يَقُولُونَ: قَدْ أَحْسَنْتَ فَقَدْ أَحْسَنْتَ. وَإِذَا سَمِعْتَهُمْ يَقُولُونَ: قَدْ أَسَأْتَ فقد أَسَأْت . رَوَاهُ ابْن مَاجَه
Ibn Mas'ud (may Allah be pleased with him) narrates: A man asked the Prophet (peace and blessings of Allah be upon him): O Messenger of Allah! How will I know whether I am good or bad? The Prophet (peace and blessings of Allah be upon him) said: "When you hear your neighbors saying that you are good, then you are good, and when you hear them saying that you are bad, then you are bad." Its chain is authentic, narrated by Ibn Majah.