Parashas Masei · Passuk 33:3 · TT note 2
Chabad.org — English translation + Rashi
Torah Temimah points to Yerushalmi Challah 2:1 (TT note on “מִמׇּחֳרַת הַפֶּסַח”).
English: “On the morrow of the Pesach” — on the morrow of the slaughter of the Pesach. And when is that? On the fifteenth.
Custom — defining “morrow of the Pesach” as the day after the fourteenth’s slaughter (the fifteenth), not the day after Yom Tov.
The verse fixes that Israel left on the fifteenth, the day after the Pesach was slaughtered on the fourteenth — clarifying parallel language in Yehoshua about eating of the produce of the land.