I say, then, that this statement of Imām al-Shāfiʿī is clear evidence that he did not distinguish between creed and practice when it comes to acting upon a solitary report. For establishing that Moses was the companion of al-Khiḍr is a matter of knowledge, not a practical ruling, as has already been explained.
What reinforces this is that Imām al-Shāfiʿī, may Allah have mercy on him, devoted an important section in al-Risālah entitled “The Proof for Establishing a Solitary Report,” in which he cited many proofs from the Quran and the Sunnah (pp. 401–453). These proofs are worded in absolute, unrestricted terms, and by that very generality they indicate that a solitary report is authoritative in matters of creed as well; his own discussion there is likewise framed in general language. He concludes that section with the words:
“Concerning the establishment of a solitary report there are hadiths—any one of them would have sufficed. Our predecessors, and the generations after them up to those we have met, have always followed this⦗1⦘ path. We have likewise been told, by those who informed us, that the scholars in the various lands have done the same.”
This, too, is stated in general terms. He also says (p. 457):
“If it were permissible for anyone to assert, in the science reserved for the elite, that the Muslims—early and later—have unanimously agreed upon affirming the solitary report and submitting to it, such that no Muslim jurist is known except that he affirmed it, then it would be permissible for me to do so. Yet I will merely say: I have never found any report of the Muslim jurists differing over the affirmation of the solitary report.”