It is narrated from Sayyiduna Hubshi bin Junadah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said to Sayyiduna Ali (may Allah be pleased with him): "You are to me as Harun was to Musa."
Hadith Referenceالمعجم الكبير للطبراني / باب الحاء / 3502