It is narrated from Hazrat Anas (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: A person's faith cannot be upright until his heart is upright, and his heart cannot be upright until his tongue is upright, and no person will enter Paradise whose neighbor is not safe from his harm.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 13048
Hadith Gradingحکم دارالسلام:إسناده ضعيف لضعف على بن مسعدة الباهلي، وقد سلف قصة الجار بإسناد صحيح، برقم: 12561