Sayyiduna Ali (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said to me: "When two parties come to you, do not judge by listening to only one of them, but listen to both sides. You will see how you judge."
Hadith Referenceمسند احمد / مسند الخلفاء الراشدين / 1285
Hadith Gradingحکم دارالسلام:حسن لغيره، و هذا إسناد ضعيف لضعف حنش