I was thinking about those two Gemaras in Avoda Zara 23b and Rosh Hashanah 13a. While it would be simple to say that one holds אין קניין לעכו''ם בארץ ישראל there is no ability of a idolater to possess land in Israel while the other Gemara holds an idolater can possess land in Israel. But clearly Tosphot [in Rosh Hashana 13a] does not make that distinction, and it occurred to me the obvious reason. Raba who holds אין קניין לעבו''ם בארץ ישראל (there is no ability of a idolater to possess land in Israel) holds that only with regard to Truma and Maasar [tithes], not when it comes to monetary ownership. And in fact Raba holds that monetary ownership even stronger than Rav Elazar. So the the Gemara in Avoda Zara can not simply be said to be of Raba.
The actual Gemara in Avoda Zara 23 says why was Israel commanded to burn the idolatrous trees when they entered into Israel? After all Israel was in the possession of Israel since it was promised to Avraham, and so the gentiles could not make the trees forbidden. And the Gemara answers that since Israel worshipped the golden calf, thus idolatry was alright to them, so the gentiles could cause those trees to becomes forbidden.
Now the way Rav Shach understands the Rambam in laws of idolatry 8:3, that Gemara in fact is like Raba that the land could not have been owned by the gentiles after it was promised to Avraham. But that answer is hard to see since even Raba holds a gentile can have monetary ownership, and that should be enough to make trees that he worships to be forbidden. So Tosphot explains that that Gemara is referring to trees that existed already in the time of Avraham, and its question refers to them.
[But I can see the answer to Rav Shach also to some degree, since the Rambam might have said that to forbid a planted tree the gentile would have to have complete ownership even as far as truma and maasar would go.]
[The other Gemara in Rosh Hashana asks how could Israel bring the omer from grain that was in Israel when they entered into the land. Was not the grain owned by gentiles? And one can not bring the omer from grain that was owned by gentiles.
The contradiction between these two Gemaras is answered by Tosphot thus: The gemara in Rosh Hashana is ok because even though Israel owned the land still the gentiles owned the grain that they grew. And the question in Avoda Zara is ok [how could gentiles cause trees owned by Israel to become idolatrous trees]--that question is a good question since Israel was commanded to destroy all the idolatrous trees even those that were around from the time of Avraham
[There is still a lot to think about here --in terms of in fact how these two gemaras relate to the issue between Raba and Rav Elazar. I recall that I wrote something about this in my little booklet on Bava Metzia.] [page 101]
However I still am wondering this question. The answer of Tosphot is that these two gemaras do not disagree. Ok. But then according to which opinion is this answer going like? It seems that it must be R. Elazar that an idolater does have to ability to possess land to take away the obligation of truma and maasar. That is the only way I can see that the Gemara in Rosh Hashana can make sense. But if so then what is the question in Avoda Zara? How can the gentiles cause to be forbidden the trees in the land of Israel? The answer ought to be simple. They have part possession. [Just like Tosphot answers for the Gemara in Rosh Hashana]. And so why does the Gemara there not simply answer the question in that way? So you must say instead that Tosphot is going like Raba that the gentile has no ability to possess land to the degree of taking away the obligation of tithes. That answers the Gemara in Avoda Zara. An das for the Gemara in Rosh Hashana the answer is the gentile has no ability to possess land that can remove the obligation of truma. But the land at the time that Israel came into the land of Canaan, the land was only collectively owned, not owned by any one individual. And in that case the gentile could own land.
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I was thinking about those two גמרות in עבודה זרה כ''ג ע''ב and ראש השנה י''ג ע''א . While it would be simple to say that one holds אין קניין לעכו''ם בארץ ישראל there is no ability of a idolater to possess land in Israel while the other גמרא holds an idolater can possess land in Israel. But clearly תוספות does not make that distinction, and it occurred to me the obvious reason. רבה who holds אין קניין לעכו''ם בארץ ישראל there is no ability of a idolater to possess land in Israel holds that only with regard to תרומה and מעשר, not when it comes to monetary ownership. And in fact רבה holds that in terms of monetary ownership even stronger than רב אלעזר. So the the גמרא in עבודה זרה can not simply be said to be of רבה. The actual גמרא in עבודה זרה כ''ג ע''ב says why was Israel commanded to burn the idolatrous trees when they entered into Israel? After all Israel was in the possession of Israel since it was promised to אברהם and so the gentiles could not make the trees forbidden. And the גמרא answers that since Israel worshipped the golden calf, thus idolatry was alright to them, so the gentiles could cause those trees to becomes forbidden. Now the way רב שך understands the רמב''ם in laws of idolatry 8:3 that גמרא in fact is like רבה that the land could not have been owned by the gentiles after it was promised to אברהם. But that answer is hard to see since even רבה holds a gentile can have monetary ownership and that should be enough to make trees that he worships to be forbidden. So תוספות explains that that גמרא is referring to trees that existed already in the time of אברהם and its question refers to them. But I can see the answer של רב שך also to some degree, since the Rambam might have said that to forbid a planted tree the gentile would have to have complete ownership even as far as תרומה and מעשר would go. The other גמרא in ראש השנה asks how could Israel bring the עומר from grain that was in Israel when they entered into the land. Was not the grain owned by gentiles? And one can not bring the עומר from grain that was owned by gentiles. The contradiction between these two גמרות is answered by תוספות thus: The גמרא in ראש השנה י''ג ע''א is ok because even though Israel owned the land, still the gentiles owned the grain that they grew. And the question in עבודה זרה is ok [how could gentiles cause trees owned by Israel to become idolatrous trees?] that question is a good question since Israel was commanded to destroy all the idolatrous trees, even those that were around from the time of אברהם.
[I am thinking that that is what Tosphot means over there in Rosh Hashana.]
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חשבתי על שתי הגמרות האלה בעבודה זרה כ''ג ע''ב וראש השנה י''ג ע''א. אמנם יהיה פשוט לומר שאחד מחזיק שאין קניין לעכו''ם בארץ ישראל, (אך אין יכולת של עובד אלילים להחזיק אדמה בישראל) ואילו הגמרא השנייה מחזיקה שעכו''ם יכול להחזיק אדמה בישראל. אך ברור שתוספות לא מבדילה את ההבחנה הזאת, ונדמה לי שהסיבה ברורה. רבה המחזיק אין קניין לעכו''ם בארץ ישראל אין יכולת של עובד אלילים להחזיק אדמות בישראל גורסת כי רק לגבי תרומה ומעשר, לא כשמדובר בבעלות כספית. ולמעשה רבה גורס כי מבחינת בעלות כספית חזקה עוד יותר מרב אלעזר. אז לא ניתן לומר שהגמרא בעבודה זרה היא רבה. גמרא בפועל בעבודה זרה כ''ג ע''ב אומר מדוע נצטוו ישראל לשרוף את העצים האלילים בעת כניסתם לישראל? אחרי הכל ארץ ישראל הייתה ברשות ישראל מאחר שהובטח לאברהם ולכן הגויים לא יכלו לאסור על העצים. והגמרא עונה שמכיוון שישראל סגדו לעגל הזהב, כך עבודת אלילים הייתה בסדר מבחינתם, כך שהגויים יכולים לגרום לאותם עצים להיות אסורים. עכשיו הדרך בה רב שך מבין את הרמב''ם בחוקי עבודת האלילים 8: 3 שלמעשה הגמרא בראש השנה לרבה שהארץ לא הייתה יכולה להיות בבעלות הגויים לאחר שהובטח לאברהם. אבל קשה לראות את התשובה הזו מכיוון שאפילו רבה מחזיק שלגוי יכול להיות בעלות כספית וזה אמור להספיק כדי להפוך עצים שהוא עובד כדי לאסור. אז תוספות מסביר כי הגמרא מתייחסת לעצים שהיו קיימים כבר בתקופת אברהם ושאלתה מתייחסת אליהם. [אבל אני יכול לראות את התשובה של רב שך גם במידה מסוימת, מכיוון שהרמב"ם אולי היה אומר שכדי לאסור על עץ נטוע, הגוי יצטרך להיות בעלות מוחלטת אפילו עד לתרומה ומעשר.] הגמרא האחרת בראש השנה שואלת כיצד יכול ישראל להביא את העומר מתבואה שהייתה בישראל כשנכנסו לארץ. האם התבואה לא הייתה בבעלות גויים? ואי אפשר להביא את העומר מדגן שהיה בבעלות גויים. את הסתירה בין שתי הגמרות הללו עונה תוספות כך: הגמרא בראש השנה י''ג ע''א היא בסדר מכיוון שלמרות שישראל היו הבעלים של האדמה, עדיין הגויים היו הבעלים של התבואה שהם גידלו. והשאלה בעבודה זרה היא בסדר [איך גויים יגרמו לעצים שבבעלות ישראל להפוך לעצים אלילים] שאלה זו שאלה טובה מאחר שישראל נצטוו להשמיד את כל העצים האלילים, אפילו אלה שהיו בסביבה עוד מימי אברהם.