(Rabanan of Kisarin citing R. Chaninah): [Even though R. Yehudah said 'when is this',] there is an argument [with Chachamim about this. It is based on the following];

"Kol ha'Makom Asher Tidroch Kaf Raglechem Bo Lachem Yihyeh'' - the Klal includes only the Prat (what the verse says later - Min ha'Midbar...) R. Yehudah says so;

Question (Chachamim, against R. Yehudah): If this discusses the borders of Eretz Yisrael [it is not needed, for it says] "meha'Midbar veha'Levanon ha'Zeh Ad ha'Nahar ha'Gadol Nehar Peras Kol Eretz ha'Chitim v'Ad ha'Yam ha'Gadol Mevo ha'Shemesh Yihyeh Gevulchem''!

Rather, if it is not needed for the borders of Eretz Yisrael, use it to teach about borders of Chutz la'Aretz (what Bnei Yisrael conquer all of Eretz Yisrael, even the rivers get Kedushas ha'Aretz. Therefore, the boat need not be Gosheshes. We explained this entire Sugya like MEICHAL HA'MAYIM.)

Consequence: If so, what David conquered in Aram Naharayim and Aram Tzovah is obligated in Ma'aseros! (GRA)

Rejection: That was different, for David left over (did not conquer all within) the borders of Eretz Yisrael, and conquered borders of Chutz la'Aretz.