It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Jibril (peace be upon him) kept enjoining me so much about the neighbour that I thought he would make him an heir."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13286