question #1 Sahih Muslim 1218c, Book 15, Hadith 161 : What is the significance of the entire area of Mina being designated as a place for sacrifice during Hajj?

I have sacrificed (the animals) here, and the whole of Mini is a place for sacrifice; so sacrifice your animals at your places. 1 have stayed here (near these rocks), and the whole of Arafat is a place for stay. And I have stayed here (at Muzdalifa near Mash’ar al-Haram and the whole of Muzdalifa) is a place for stay (i. e. one is permitted to spend night in any part of it, as one likes).