He explains his objection: And just as a lamp, which is made for this purpose, for lighting, when he did not light it, he is permitted to move it, a bed, which is not made for that purpose, for placing money on it, all the more so moving it would be permitted. Rather, if it was stated, it was stated as follows: Rav Yehuda said that Rav said: A bed that one designated for money to be placed upon it, if one left money upon it one day, it becomes designated for that purpose and it is prohibited to move it on Shabbat. If one did not leave money upon it, it is permitted to move it on Shabbat. A bed, which one did not designate for money to be placed upon it, if there is money upon it on Shabbat itself, it is prohibited to move it on Shabbat. If there is not money on it, it is permitted to move it. And that is only when there was not money on it during the twilight period between Shabbat eve and Shabbat. If there was money on it at that time, the bed itself becomes set aside due to prohibition for the entire Shabbat, even if the money fell off the bed in the course of the day.

Ulla said: Rabbi Eliezer raised an objection to Rav’s statement from that which we learned in a mishna. This mishna deals primarily with the laws of ritual impurity and discusses the relationship between a wagon and its undercarriage [mukheni], the system of wheels and the frame at the base of the wagon. And the Sages said: The wagon’s undercarriage, when it is detachable from the wagon, it is not considered connected to it and they are considered independent units as far as the halakhot of ritual impurity are concerned. And it is not measured with it. This refers to calculating the volume of forty se’a, as a vessel with a volume larger than forty se’a does not have the legal status of a vessel and cannot become ritually impure. And the undercarriage likewise does not protect together with the wagon in a tent over the corpse. A large wagon is considered a tent in and of itself and the vessels inside the wagon do not become impure if the wagon is over a corpse. However, the undercarriage is not included with the wagon in this regard. If a hole in the wagon is sealed by the undercarriage, it is not considered sealed with regard to preventing ritual impurity. And, likewise, one may not pull the wagon on Shabbat when there is money upon it.

By inference: If there is not money on it, one is permitted to move the wagon even though there was money on it at twilight. In this mishna, the prohibition is contingent exclusively on whether or not there is money on the wagon at that time. The Gemara answers: That mishna is in accordance with the opinion of Rabbi Shimon, who is not of the opinion that there is a prohibition of set-aside. And Rav holds in accordance with the opinion of Rabbi Yehuda. Since according to Rabbi Yehuda there is a prohibition of set-aside, the wagon became set aside from use during the twilight period and remains prohibited for the entire Shabbat.