Al-Adab Al-Mufrad, Book 6, Hadith 104 (English)

Ibn 'Umar reported that the Messenger of Allah, may Allah bless him and grant him peace, said, "Jibril kept on recommending that I treat my neighbours well until I thought that he would order me to treat them as my heirs."

حَدَّثَنَا مُحَمَّدُ بْنُ مِنْهَالٍ، قَالَ‏:‏ حَدَّثَنَا يَزِيدُ بْنُ زُرَيْعٍ، قَالَ‏:‏ حَدَّثَنَا عُمَرُ بْنُ مُحَمَّدٍ، عَنْ أَبِيهِ، عَنِ ابْنِ عُمَرَ قَالَ‏:‏ قَالَ رَسُولُ اللهِ صلى الله عليه وسلم‏:‏ مَا زَالَ جِبْرِيلُ يُوصِينِي بِالْجَارِ حَتَّى ظَنَنْتُ أَنَّهُ سَيُوَرِّثُهُ‏.‏

sunnah.com