Parashas Masei · Passuk 33:52 · TT note 1
Chabad.org — English translation + Rashi
Torah Temimah points to Sotah 34a (TT note on “וְהוֹרַשְׁתֶּם”).
English: While Israel was still in the Jordan, Yehoshua said to them: Know on what condition you are crossing the Jordan — on condition that you drive out the inhabitants of the land from before you, as it is said “and you shall drive out all the inhabitants of the land from before you.”
Halakhic condition attached to entry into the Land — the conquest command as the terms of the crossing.
Entry into the Land was conditional on the obligation to dispossess its inhabitants; Yehoshua made that condition explicit while they were still in the Jordan.