Bava Batra

If he has unloaded them  and brought them into his  house [and] fixed [the price] before measuring, neither of them may withdraw.  [If] measuring took place before the price has been fixed, both may withdraw.  Now, since the vessel of the seller, [if it is] on the premises of the buyer, does not serve as a means of retaining possession for him,  the vessel of the buyer also [if it is] on the premises of the seller does not serve as a means of acquiring possession for him!  R. Nahman b. Isaac replied: [The law quoted  refers to the case] when [the goods] were emptied out [from the seller's sacks into the territory of the buyer]. Raba [remarked] indignantly: Does it state 'he emptied them'? The statement reads, 'he unloaded them'!  But, said Mar son of R. Ashi: [The law here refers] to bundles of garlic. Huna the son of Mar Zutra said to Rabina: Observe that it has been said, 'he unloaded them';  what matters it, then, [whether the price had been] fixed or not? — He [Rabina] replied: [When the price] has been fixed, each [of the parties] acquiesces [in the sale, but when a price] has not been fixed, none [of them] acquiesces. Rabina said to R. Ashi: come and hear! [It has been stated:]  Both Rab and Samuel hold that a man's vessel acquires for him ownership everywhere. Does not this ['everywhere'] include the premises of the seller? — [In the case spoken of] there,  [the other replied, the seller] said to him 'go and acquire ownership'. We have learnt elsewhere:  Ownership of landed property  is acquired by means of money. deed and possession;  and movable property  is acquired only by meshikah.  The following reported statement has been attributed in Sura to R. Hisda; at Pumbeditha, to R. Kahana or — according to others — to Raba: [The law of meshikah] has been taught, with reference only to [heavy] objects which are not usually lifted, but objects which are usually lifted can be acquired by hagbahahl  only; not by meshikah. Abaye sat lecturing on this law, [when] R. Adda b. Mattenah raised the following objection. [It has been taught]:  He who steals a purse on the Sabbath  is liable [to make restitution], because the obligation [to pay restitution], for the theft 'has preceded  the offence against the prohibition of the Sabbath.  If he was dragging [it]  as he was moving out, he is exempt [from the payment of restitution]  because here the offences relating to the desecration of the Sabbath and to theft have been committed simultaneously.  Now, surely. a purse is an object which is usually lifted, and yet it is acquired by meshikah!  He replied unto him: When [the purse has] a cord. 'I also', said R. Adda, 'speak of one with a cord' [and yet it is small enough to be lifted]! — [Abaye] replied: [I say that the law refers to] a thing  [so heavy] that it requires a cord. Come and hear: [It has been taught:  If the purchase was] on the premises of the seller, [the buyer] does not acquire possession until he lifts it or removes it from the seller's premises. This proves clearly that an object which can be lifted may be acquired in accordance with one's desire, either by 'lifting' or by meshikah!  R. Nahman b. Isaac replied: What has been taught is to be taken — disjunctively; that which can be lifted [is acquired] by lifting, and that which has to be pulled [is acquired] by meshikah.