Musar for Shabbat 138:3
ואמר אביי הכל מודים בתרומה שאין חייבין עליה חומש עד שישגוג בלאו שבה הכל מודים מאן רבי יוחנן פשיטא כי אמר רבי יוחנן היכא דאיכא כרת היכא דליכא כרת לא מהו דתימא מיתה במקום כרת עומדת וכי שגג במיתה נמי ליחייב קמ"ל רבא אמר מיתה במקום כרת עומדת וחומש במקום קרבן קאי:
— This agrees with Monabaz. (Another version: Who is the authority for this? Shall we say, Monabaz? But then it is obvious! seeing that in the whole Torah, where it [liability to a sacrifice] is not an anomaly, Monabaz rules that unawareness of the sacrifice constitutes unawareness, how much more so here that it is an anomaly!<span class="x" onmousemove="('comment',' V. n. 2. ');"><sup>4</sup></span> Hence it must surely be the Rabbis, and this refutation of Abaye is indeed a refutation.)<span class="x" onmousemove="('comment',' The passage 'Another … refutation' is bracketed in the edd., and Rashi deletes it. For in fact the ruling is necessary according to Monabaz too. For whereas elsewhere ignorance is constituted by unawareness either of the forbidden nature of the act or of the sacrifice it entails, here the former does not constitute ignorance, and there must be unawareness of the liability to a sacrifice. This does not follow from Monabaz's other ruling and so must be stated. ');"><sup>5</sup></span>