Musnad Abu Ya'la al-Mawsili 249:10

Abu al-Ash'ath Ahmad ibn al-Miqdam al-'Ijli narrated to us, 'Ubayd ibn al-Qasim narrated to us, al-'Ala' ibn Tha'labah narrated to us, from Abu al-Malih al-Hudhali, from Wathilah ibn al-Asqa', who said: I drew near to the Prophet, peace and blessings of Allah be upon him, in the Mosque of al-Khayf. His companions said to me, "Move aside, O Wathilah," meaning: move away from the face of the Prophet, peace and blessings of Allah be upon him. The Prophet, peace and blessings of Allah be upon him, said, "Leave him, for he has only come to ask." I drew near and said, "May my father and mother be sacrificed for you, O Messenger of Allah. Will you give us a religious ruling (fatwa) regarding a matter we may take from you after you are gone?" He said, "Let your own soul give you a religious ruling." I said, "And how can I do that?" He said, "Leave what makes you doubt for what does not make you doubt, even if the muftis give you a fatwa." I said, "And how can I know that?" He said, "Place your hand upon your heart, for the heart finds tranquility in the lawful and does not find tranquility in the unlawful. Indeed, the pious Muslim leaves the small [sins] for fear of falling into the great [sins]." I said, "May my father and mother be sacrificed for you, what is tribalism (asabiyyah)?" He said, "The one who helps his people in injustice." I said, "And who is the greedy one?" He said, "The one who seeks earnings from other than their lawful source." I said, "And who is the pious one?" He said, "The one who stops at doubt." I said, "And who is the believer?" He said, "The one whom people trust with their wealth and their blood." I said, "And who is the Muslim?" He said, "The one from whose tongue and hand the Muslims are safe." I said, "And which jihad is best?" He said, "A word of truth in the presence of a tyrannical ruler."