Reference for Yevamot 226:6

דבר תורה שוטה מתגרשת והא אמר דבי רבי ינאי (דברים כד, א) ונתן בידה מי שיש לה יד לגרש עצמה יצתה זו שאין לה יד לגרש עצמה

but this one<span class="x" onmousemove="('comment',' The imbecile. ');">¹⁴</span> is excluded since she is incapable of accepting her divorce; and, furthermore, it was taught at the school of R. Ishmael, And sendeth her out of his house,<span class="x" onmousemove="('comment',' Deut. XXIV, 1. ');">¹⁵</span> only one who, when he sends her out, does not return, but this one<span class="x" onmousemove="('comment',' The imbecile. ');">¹⁴</span>

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