Did Aaron die on Mount Hor or at Moserah?

The likeliest explanation is that Mosera was the camp at the foot of Mount Hor, and Aaron died on the mountain above it. When Deuteronomy says “there Aaron died”, ‘there’ means the place where Israel was encamped at the time. Numbers tells the event in detail: Moses, Aaron and Eleazar went up the mountain “in the sight of all the congregation”, Aaron died on the summit, and Moses and Eleazar came down (20:27-28). Deuteronomy gives only the camp, because Moses is not retelling Aaron’s death. He is reminding Israel that God, who had been angry enough with Aaron at Sinai to destroy him (9:20), kept the priesthood going after Aaron’s death through his son Eleazar (10:6).

The order of the places is explained by two journeys through the same region. Numbers 33:30-33 lists the camps of an earlier march in the years of wandering: Moseroth, Bene-jaakan, Hor-hagidgad, Jotbathah. Deuteronomy 10:6-7 describes the march of the fortieth year, when Israel left Kadesh for Mount Hor and then went south (Numbers 20:22; 21:4), camping at some of the same wells: this time from Beeroth Bene-jaakan to Mosera, the reverse of the earlier order, and then south again to Gudgodah and Jotbath. ‘Moseroth’ is the plural form of ‘Mosera’, and Gudgodah a shorter form of Hor-hagidgad. Keil and Delitzsch, who set out this explanation, conclude that the two lists, though they name the same places, describe different journeys.

Mosera, the district of Mount Hor

Ibn Ezra, whom Gill seems to favour, took Mosera in Deuteronomy as the name of the wilderness around Mount Hor, a different place from the earlier camp Moseroth. On this view too Aaron died on Mount Hor, in the district called Mosera.

Numbers 33 lists only Kadesh and Mount Hor for this stage of the fortieth year (33:37), so the explanation above assumes that its list of the last journey is not complete. None of these camps can now be located with certainty.