It is narrated from Qays bin Abbad (may Allah have mercy on him) that he said: "I said to Sayyiduna Ali (may Allah be pleased with him): Tell me about this march of yours: is it a covenant that the Messenger of Allah (peace and blessings be upon him) made with you? Or is it merely an opinion that you formed yourself?"
No one narrated this hadith from Yunus (may Allah have mercy on him) except Ibn Ulayyah (may Allah have mercy on him).
Hadith Referenceالمعجم الأوسط / باب الألف / 575
Hadith Takhrij«أخرجه الضياء المقدسي فى «الأحاديث المختارة» برقم: 704، 705، وأبو داود فى «سننه» برقم: 4666، وأحمد فى «مسنده» برقم: 1287، وابن حجر فى «المطالب العالية» برقم: 4394 / 1، 4394 / 2، والطبراني فى «الأوسط» برقم: 1278»