question #3 Sahih Muslim 677f, Book 5, Hadith 383 : What significance did the group of seventy reciters hold that led to the Prophet’s deep sorrow upon their loss?

Never did I ace the Messenger of Allah (ﷺ) so much grieved (at the loss of a) small army as I saw him grieved at those seventy men who were called” reciters” (and were killed) at Bi’r Ma’una; and he invoked curse for full one month upon their murderers.