Bava Batra 74A

וגנו אפרקיד. והוה זקיפא ברכיה דחד מינייהו, ועיל טייעא תותי ברכיה כי רכיב גמלא, וזקיפא רומחיה ולא נגע ביה. פסקי חדא קרנא דתכלתא דחד מינייהו, ולא הוה מסתגי לן. אמר לי: דלמא שקלת מידי מינייהו? אהדריה, דגמירי דמאן דשקיל מידי מינייהו לא מסתגי ליה. אזלי אהדרתיה, והדר מסתגי לן.

and they were lying on their backs. And the knee of one of them was elevated, and he was so enormous that the Arab entered under his knee while riding a camel and with his spear upright, and he did not touch him. I cut one corner of the tekhelet garment that contains tzitzit of one of them, and we were unable to walk. The Arab said to me: Perhaps you took something from them? Return it, as we know by tradition that one who takes something from them cannot walk. I then returned the corner of the garment, and then we were able to walk.

כי אתאי לקמיה דרבנן, אמרו לי: כל ״אבא״⁠ – חמרא, וכל ״בר בר חנה״⁠ – סיכסא! למאי הלכתא עבדת הכי? למידע אי כבית שמאי אי כבית הלל? איבעי לך למימני חוטין ולמימני חוליות.

When I came before the rabbis, they said to me in rebuke: Every Abba is a donkey, and every bar bar Ḥana is an idiot. For the purpose of clarifying what halakha did you do that? If you wanted to know whether the halakha is in accordance with the opinion of Beit Shammai or in accordance with the opinion of Beit Hillel, as to whether there are 4 or 3 threads and joints in tzitzit, in that case there was no need to take anything with you, as you should have simply counted the threads and counted the joints.

אמר לי: תא אחוי לך הר סיני. אזלי, חזאי דהדרא ליה עקרבא, וקיימא כי חמרי חוורתי. שמעתי בת קול שאומרת: ״אוי לי שנשבעתי; ועכשיו שנשבעתי ⁠– מי מפר לי?״

Rabba bar bar Ḥana continues his account. That Arab also said to me: Come, I will show you Mount Sinai. I went and saw that scorpions were encircling it, and they were standing as high as white donkeys. I heard a bat kol saying: Woe is Me that I took an oath; and now that I took the oath, who will nullify it for me?