And from this it is explained that what our teacher, the Rema, wrote in section 8, that all these are the words of the Rambam but there are those who disagree, as he wrote at the beginning of siman 354 and 356, and even a change that returns to its original state, such as dust that he made into bricks, even though he did not acquire it as mentioned above in siman 360, he nevertheless acquires the improvement and must return the value of the improvement to him, thus far his words; the explanation of his words is that there are those who disagree and hold that birth and shearing are considered a change. And that which he wrote, that in a change that returns to its original state he must return the improvement to him, this is because this is not an improvement that comes on its own, and the improvement came through his exertion. And in this, all the poskim are equal with the Rambam, as our teacher, the Beit Yosef, wrote in section 9. This is his wording: In what case does this apply? Regarding an improvement that comes on its own, such as shearings and offspring; but if it was lean and he spent money on it and fattened it, even before ye'ush, he takes the improvement of the fattening from the victim of the robbery, and so too anything similar to this regarding an improvement that involves expenditure. Thus far his words. And therefore our teacher, the Rema, emended his words before this section, because in this law the poskim do not disagree with the Rambam. And our teacher, the Rema, innovated in his words that it is not specifically an improvement through expenditure, but even an improvement not through expenditure but through exertion, such as with dust that he made into bricks, he also acquires the improvement even before ye'ush, for exertion is like expenditure, and the Rambam would also admit to this [and what the Be'er HaGolah wrote in letter 5 does not appear correct to me, and the Rambam holds like all the poskim that ye'ush is not an acquisition at all, and only regarding kiddushin, due to the stringency of a married woman, did the poskim in Even HaEzer concern themselves, as written in siman 353, and examine it carefully].
ומזה מתבאר דמ"ש רבינו הרמ"א בסעיף ח' דכל אלה דברי הרמב"ם אבל יש חולקין וכמ"ש ר"ס שנ"ד ושנ"ו ואפילו שינוי החוזר לברייתו כגון עפר ועשאו לבנים אע"ג דלא קנה כדלעיל סי' ש"ס שבח מיהו קנה וצריך להחזיר לו שבחו עכ"ל ביאור דבריו דיש חולקין וס"ל דלידה וגיזה הוי שינוי וזה שכתב דבשינוי החוזר לברייתו צריך להחזיר לו השבח זהו מפני שאין זה שבח דממילא והשבח בא ע"י טרחתו ובזה שוים כל הפוסקים עם הרמב"ם וכמ"ש רבינו הב"י בסעיף ט' וז"ל בד"א בשבח הבא מאליו כגון גיזות ולדות אבל אם היתה כחושה והוציא עליה ופטמה אפילו לפני יאוש נוטל מהנגזל שבח הפיטום וכן כל כיוצא בזה משבח שיש בו הוצאה עכ"ל ולכן הגיה רבינו הרמ"א דבריו קודם סעיף זה משום דבדין זה אין מחולקים הפוסקים עם הרמב"ם ורבינו הרמ"א חידש בדבריו דלאו דוקא שבח שע"י הוצאה אלא אפילו שבח שלא ע"י הוצאה אלא ע"י טירחא כמו בעפר ועשאו לבנים ג"כ קנה השבח אפילו קודם יאוש דטירחא הוי כהוצאה וגם הרמב"ם יודה בזה [ומ"ש הבאה"ג באות ה' ל"נ והרמב"ם ס"ל ככל הפוסקים דיאוש אינו קנין כלל ורק בקדושין מפני חומר א"א חששו הפוסקים באה"ע כמ"ש בסי' שנ"ג ודוק]: