ONE HUNDRED AND TWENTY-THREE (Bemidbar 33,39)
Rambam in Halacha (Chanukah 3, 12), brings that the 123 years of Aharon’s life are a sign for the 123 times the word 'הללויה' that the Jews answered the leader during the recitation of Hallel. Life of Aharon “lover of the Jews” expresses the unity that the Jews seek in Hallel.
The Amount of Couples Aharon Counseled Daily
וכתב את האלת האלה הכה בספר ומחה אל מי המרי
The Kohen shall inscribe these curses on a scroll and erase it into the bitter waters (5:23). From here the Gemara learns how great it is to create Shalom Bayis between husband and wife, so much so, that HaShem allowed His name to be erased to bring harmony between them. The Kohen in the desert was Aharon.
R’ Moshe Aharon Stern points out an amazing thing about Aharon HaKohen. Aharon loved peace and pursued peace. The Kallah Rabasi writes that at Aharon HaKohen’s funeral there were 80,000 boys with the name Aharon who followed his coffin. They were children of couples whose marriages were saved due to Aharon HaKohen. As a sign of gratitude these couples named a son after Aharon.
This means that throughout the 40 years in the desert, Aharon helped on average 5 to 6 couples a day (5.6 x 355 x 40 = 79,520)! The Moneh Mispar adds that in reality the amount of couples was probably much more, being that there were probably many girls born who simply could not be given the name Aharon.