Bava Batra — Daf 66b

והא קיימא לן דרבנן ועוד האמר ר' יוסי בן ר' חנינא בדף של מתכת מחלוקת

לעולם רבנן היא ושאני שאיבה דרבנן

אי הכי אפילו חקקו ולבסוף קבעו נמי שאני התם דאיכא תורת כלי עליו בתלוש

בעי רב יוסף מי גשמים שחשב עליהם להדיח את האיצטרובלין מהו לזרעים

אליבא דרבי אליעזר דאמר כל המחובר לקרקע הרי הוא כקרקע לא תיבעי לך כי תיבעי לך אליבא דרבנן דאמרי אינו כקרקע מאי תיקו

שלח ליה רב נחמיה בריה דרב יוסף לרבה בריה דרב הונא זוטי לנהרדעא כי אתיא הך איתתא לקמך

But are not all agreed that it was decreed by the Rabbis [on their own authority]? And further, R. Jose son of R. Hanina has said that the dispute [between R. Eliezer and the Rabbis] concerned a board of metal!  We must therefore say that in truth the above statement follows the Rabbis, and that they make a difference in the case of 'drawn' water  because its uncleanness was decreed [only] by the Rabbis. If that is the case,  then even if he first hollowed it and then fixed it [it should not spoil the mikweh]?  — There where it was hollowed and then fixed the case is different, because it was in the category of a vessel while still unfixed. R. Joseph raised the following question: If a man, seeing the rain descend on the casing of his handmill, decided to regard this as a washing, what is its effect upon seeds?  If we accept the opinion of R. Eliezer, that anything attached to the ground is in the same category as the ground, no question will arise.  Where the question arises is if we accept the view of the Rabbis who said that it is not in the same category as the ground?  — This question must stand over. R. Nehemiah the son of R. Joseph sent to Rabbah the son of R. Huna Zuti at Nehardea the following instruction: When this woman presents herself to you,