Parashas Eikev · Passuk 10:6
From Beeroth-bene-jaakanaBeeroth-bene-jaakan Lit. “wells of Bene-jaakan”; cf. Num. 33.31–32. the Israelites marched to Moserah. Aharon died there and was buried there; and his son Eleazar became priest in his stead.
Torah Temimah points to Yerushalmi Yoma 1:1.
TT lemma: מוסרה שם מת אהרן, וכי במוסרה מת והלא בהר ההר מת (פ' מסעי), אלא מכיון ש (unit 1 of 2).
English: “At Moserah Aharon died” — but he died at Hor HaHar (Masei)? Rather: when he died the clouds of glory departed, the Canaanites sought to attack, Israel wished to return to Egypt and traveled eight stages backward (counting the stations from Hor HaHar back to Moserah). The tribe of Levi pursued them, blood was shed, and they said: Who caused this bloodshed? That we did not perform kindness with that righteous man. They sat and eulogized him, and the Torah counts the place of that mourning as where Aharon “died.”
Custom (Yerushalmi — Moserah as site of mourning for Aharon)
The Torah places Aharon’s death at Moserah because of the national crisis and the eulogy that followed the reverse march.