Comentario sobre Números 20:23

על גבול ארץ אדום BY THE BOUNDARY OF THE LAND OF EDOM — This (the statement that Aaron died here) tells us that because they here wished to join themselves in close friendship with the wicked, a breach was made in their works and they had to lose this righteous man, Aaron. Similarly does the prophet say, (II Chronicles 20:37) “Because thou hast joined thyself with Ahaziah, the Lord hath made a breach in thy works” (Midrash Tanchuma, Chukat 14).

ויאמר ה׳…על גבול ארץ אדום. G'd said to Moses…on the border of the land of Edom, etc. The reason the Torah described the location as the border of the land of Edom was to show that the proximity of the wicked Edomites contributed to Aaron's death at that time. I have found a somewhat puzzling statement in the Yalkut Shimoni on our verse (item 764). The Midrash accuses: "because you befriended yourself with the wicked," Aaron died as a result of the Israelites (or Moses and Aaron?) befriending Edom." Thus far the Yalkut. It is clear to me that this is a reference to the words על גבול. This also explains why the Torah added the word לאמר in our verse. G'd commanded Moses to tell the Israelites about this little detail, i.e. that because they made a point of befriending the wicked this contributed to the untimely death of the righteous. But for that incident Aaron might have lived a few months longer although death had been decreed for him previously.

V. 23. על גבול ארץ אדום, so auch Kap. 33, 38: בקצה ארץ אדום. Es gab noch einen Berg Hor an der Nordwestgrenze von Palästina (Kap. 34, 7), weshalb diese nähere Bezeichnung notwendig war.