Sayyiduna Ali (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) once instructed me to offer two rams in sacrifice on his behalf, so I will continue to offer sacrifice on his behalf until the end.
Hadith Referenceمسند احمد / مسند الخلفاء الراشدين / 1279
Hadith Gradingحکم دارالسلام:إسناده ضعيف لجهالة أبي الحسناء و ضعف شريك