Hadith.3233 - Dawud ibn al-Husayn narrated from Umar ibn Hanzala, from Abu Abdullah (as), who said
I asked about two men who each selected a person and agreed that they would act as arbiters regarding their rights. However, they disagreed in their judgments, and both differed in their understanding of our traditions.
Imam (as) said: "The ruling should be based on the judgment of the one who is more just, more knowledgeable in jurisprudence, more truthful in narrating hadith, and more pious. The ruling of the other should not be considered."
I said: What if both of them are equally just and approved by our companions, and neither is superior to the other?
Imam (as) replied: "In such a case, their narrations from us regarding the matter they have judged should be examined. What is unanimously agreed upon by your companions should be taken from our rulings, and what is singular and not well-known among your companions should be disregarded. Indeed, what is unanimously agreed upon is our ruling, and there is no doubt in it. Matters are of three kinds: a matter whose correctness is clear and should be followed, a matter whose error is clear and should be avoided, and a matter that is ambiguous, whose judgment should be referred to Allah (swt), the Almighty and Glorious."
The Messenger of Allah (swt), peace and blessings be upon him and his family, said: "That which is lawful is clear, and that which is unlawful is clear, and between them are doubtful matters. Whoever avoids the doubtful matters has saved himself from falling into the unlawful, and whoever indulges in the doubtful matters has committed the unlawful and will perish without realizing it."
I said: What if both narrations from you are well-known and have been transmitted by trustworthy individuals?
Imam (as) said: "Consider the one whose ruling aligns with the Book of Allah (swt) and the Sunnah and contradicts the general public, and adhere to it."
I said: May I be your ransom! If we find that one of the narrations agrees with the general public while the other contradicts it, which one should we follow?
Imam (as) said: "Follow the one that contradicts the general public, for therein lies guidance."
I said: May I be your ransom! What if both narrations agree with the general public?
Imam (as) said: "Look at what their rulers and judges are inclined towards; leave that and take the other."
I said: What if their rulers and judges agree with both narrations?
Imam (as) said: "If that is the case, then delay acting upon it until you meet your Imam, for holding back in doubtful matters is better than plunging into destruction."