i was puzzling over what Rav Shach says about the law that physical money acquires by the law of the Torah, but there was a worry that the seller might leave the acquired object to be burnt and thus not be required to pay back the money given to him by the buyer. So, the sages decided that only pulling or picking up of the object causes acquisition. I looked that the gemara Bava Metzia page 48 and the gemara Avoda Zara page 71 and 63 and still had zero idea what is going on. I went to dip in the sea, and on the way back it occurred to me what Rav Shach might be saying. I think he intends to ask this: the Rambam wrote that a Jew that buys an object from a gentile, and gives him money of hekdesh (that belongs to the Temple), but has not picked up the object, the Jew has committed the sin of using that which belongs to the Temple for a secular purpose (meila). However, if the Jew buys from another Jew with money of hekdesh, but has not yet picked up the object, he has not committed meila until he picks up the object. I think Rav Shach finds this difficult because picking up is a decree of the sages, and yet by the law of the Torah, money acquires. So, the Jew should be liable for meila immediately when he pays with money of hekdesh (even when he buys from another Jew). I think Rav Shach at first wants to answer this based on the approach of the Baal Hameor. The Baal Hameor hold the sages did not nullify acquisition by money. Rather, they held money does acquire, but that either the buyer or seller can nullify the deal until the acquired object is picked up by the buyer. [But both the object and the money still need to exist. If the object, is destroyed, the sale cannot be nullified. ] [This means that the Baal Hameor agrees that the law is like R. Yochanan but interprets it differently than the Rif. Thus, we can now understand the Rambam. The law is that money acquires, but the law of meila is not applicable until the sale is final and neither party can renege on the sale.] Thus, we can now understand the Rambam. The law is that money acquires, but the law of meila is not applicable until and neither party can renege on the sale.] ----------------------------------------------------------------------------I was puzzling over what רב שך says about the law that physical money acquires by the law of the Torah, but there was a worry that the seller might leave the acquired object to be burnt and thus not be required to pay back the money given to him by the buyer. So, the sages decided that only pulling or picking up of the object causes acquisition. I looked that the גמרא בבא מציעא page מ''ח and the גמרא עבודה זרה page ס''ג and ע''א and still had zero idea what is going on. I went to dip in the sea, and on the way back it occurred to me what רב שך might be saying. I think he intends to ask this: the רמב’’ם wrote that a Jew that buys an object from a gentile, and gives him money of כסף של הקדש (that belongs to the Temple), but has not picked up the object, the Jew has committed the sin of using that which belongs to the Temple for a secular purpose (מעילה). However, if the Jew buys from another Jew with money of הקדש, but has not yet picked up the object, he has not committed מעילה until he picks up the object. I think רב שך finds this difficult because picking up is a decree of the חכמים, and yet by the law of the תורה, money acquires. So, the Jew should be liable for מעילה immediately when he pays with money of הקדש (even when he buys from another Jew). I think רב שך at first wants to answer this based on the approach of the בעל המאור. The בעל המאור hold the sages did not nullify acquisition by money. Rather, they held money does acquire, but that eithr the buyer or seller can nullify the deal until the acquired object is picked up by the buyer. [But both the object and the money still need to exist. If the object, is destroyed, the sale cannot be nullified.] [This means that the בעל המאור agrees that the law is like ר' יוחנן ,but interprets it differently than the רי''ף. Thus, we can now understand the רמב''ם. The law is that money acquires, but the law of מעילה is not applicable until the sale is final, and neither party can renege on the sale.] Thus, we can now understand the רמב''ם. The law is that money acquires, but the law of מעילה is not applicable until and neither party can renege on the sale. Then in the second part of רב שך’s answer, he explains how this might be so because in another case he finds where a deal has been made, but even though there is a monetary acquisition, the fact that one party can change his mind makes the acquisition incomplete.--rav shach also brings from the achronim that the the rambam does not hold with change of domain in terms of meila, only getting benefit. this fact explains the law that meila applies only when the deal is more than final; it can not be reversed.---------------------Then in the second part of רב שך’s answer, he explains how this might be so because in another case he finds where a deal has been made, but even though there is a monetary acquisition, the fact that one party can change his mind makes the acquisition incomplete. רב שך also brings from the אחרונים that the רמב''ם does not hold with change of domain in terms of מעילה, only getting benefit. This fact explains the law that מעילה applies only when the deal is more than final; it can not be reversed.