What does "Al-Pi Hashem" refer to?
Rashi: It refers (not only to "Vaya'al Aharon, but also
) to "Vayamos Sham"
- to teach us that Aharon died by a kiss from Hashem.
See Sifsei Chachamim.
As is evident from the Neginos.
Refer to Bamidbar, 20:1:4:1.