Narrated `Aisha
It (i.e. Al-Abtah) was a place where the Prophet (ﷺ) used to camp so that it might be easier for him to depart.
Narrated Ibn `Abbas
Staying at Al-Mahassab is not one of the ceremonies (of Hajj), but Al-Mahassab is a place where Allah's Messenger (ﷺ) camped (during his Hajjat-al-Wida).