Shalom Rachmiel,

In order to address your question properly, it is helpful to build the Sugya from its foundation and then return to the practical issue you raised.

The basic definition of Kinyan Hagbahah is that the buyer lifts the object, or causes it to be lifted, and through that act acquires it. This emerges from the Sugya in Bava Basra 86, where items whose normal manner is to be lifted are acquired through Hagbahah. The reason, as explained by the Rishonim and formulated by the Sma (Choshen Mishpat 197:3), is that whatever is in a person's hand is considered as though it is in his Reshus. Hagbahah is therefore an act of bringing the object under his control. For this reason, Hagbahah works even in the seller's Reshus. There is no need to remove the object from the seller's property; the act of lifting itself creates the Kinyan.

Accordingly, in the Sugya of the elephant standing on bundles of twigs, the issue is not how to remove the animal from the seller's Reshus, but how to create a Halachically valid act of Hagbahah for something that cannot realistically be lifted by hand. The Gemara suggests placing it on bundles so that it becomes elevated, and Tosfos (Kidushin 26a, DH Iy Nami; see also Bava Kama 98) writes that even if one merely causes the object to be lifted, that suffices for Hagbahah.

The Rishonim disagree regarding the required height of Hagbahah. Rashi (Kidushin 26a, DH b'Chavilei Zemoros, and Rashbam in Bava Basra 86b, DH she'Harei) writes that one must lift the object three Tefachim. His reasoning is that within three Tefachim we apply Lavud, and the object is considered Halachically attached to the ground. Once it is raised three Tefachim, it exits the Halachic status of Lavud and is clearly elevated. According to Rashi, the "name" of Hagbahah depends on exiting Lavud.

Rabeinu Tam in Tosfos (DH Iy Nami) maintains that one Tefach is sufficient. Even though, for the laws of Mechitzos, Lavud still applies within three Tefachim, Tosfos holds that the definition of Hagbahah for Kinyan purposes does not depend on the technical rule of Lavud. Rather, it depends on a recognizable act of lifting. A Tefach is a Halachically significant measure in many areas, and once the object has been lifted in a noticeable way, it is considered Hagbahah, even if it remains within three Tefachim of the surface.

Thus, according to all views, Hagbahah is not about removing the object from the seller's Reshus, but about giving the object the status of being lifted from the place upon which it rests. The dispute is whether that status requires exiting Lavud relative to the surface beneath it (three Tefachim, per Rashi) or merely a recognizable act of lifting (one Tefach, per Tosfos).

As for what is considered "the ground" for this purpose, the point of reference is the surface upon which the object is actually resting. There is no need to define "ground" as natural earth; the relevant measure is the height relative to the surface from which it is being lifted.

One may add a conceptual question. If, hypothetically, the buyer, seller, and elephant were all standing suspended in midair, would Rashi require lifting an additional three Tefachim in order to exit Lavud in relation to that new point of reference, or would any noticeable lifting suffice since there is no ordinary ground beneath? The answer would depend on whether Rashi's requirement is specifically about exiting Lavud from the surface below, or about exiting proximity to the object's place of rest more generally.

I hope this helps.

Kol Tuv,

Aharon Steiner