Sleeping in a certain part of the mosque/markaz

One of the chapters in Sahih Al-Bukhari – “Men sleeping in the mosque”
Anas (R.A) narrates, that a group from UKL came to Prophet (S.AW) and they remained within suffah. Abdur Rahman bin Abu Bakr (R.A) said that the people of suffah were poor
Suffah = A platform which was part of the mosque of Prophet (S.AW).