Bava Batra 86 - Pulling is Ineffective if Lifting is Possible
As we have learned elsewhere , movable items can be formally acquired by pulling them into the domain of the buyer. However, this is only true for items that are not normally lifted. Items that are normally lifted can't be acquired by pulling at all.
But is that true? Consider the following case: one who steals a bag of money on Shabbat by pulling it out of the house is not liable to pay, since he is liable with his life for carrying on Shabbat. We see that he does acquire the bag by pulling, even though normally money bags are lifted!
Rebuttal: you know what we are dealing with here? A bag that's too big to be lifted. Therefore, the rule stands, and normally pulling is ineffective as a method of acquisition if lifting is possible.