Bismillahir Rahmanir Raheem
Assalamu 'Alaykum wa Rahmatullahi wa Barakatuhu,
Jazakallah for your question.
If you ever begin to study the books of 'Sirah', then they are written while being referenced towards the ahaadith-e-mubaarikah.
Sirah of the Messenger of Allah
Salla Allahu ta'ala alayhi wa Sallam, will tell you, that when the Messenger of Allah
Salla Allahu ta'ala 'alayhi wa Sallam, had migrated from Mecca to Madina-tul-Munawwarah, they were so poor, that Allahs Messenger
Salla Allahu ta'ala 'alayhi wa Sallam decided to have ties of brotherhood between the 'Ansar' of Madinah, and the 'Muhajirin' of Mecca, so that those who had migrated i.e. performed 'hijrah', had no longer to remain poor, as there would be hands that would help them.
It was during this time, that some of the Companions of the Messenger of Allah
Salla Allahu ta'ala 'alayhi wa Sallam, decided that they did not require a house, or brotherhood with one of the 'ansaar', so that at the time of need, they could be helped, nor a business of any sort, so that they could have a regular income, they had decided to stay in the presence of the Messenger of Allah
Salla Allahu ta'ala 'alayhi wa Sallam, and be at His service, so that they could learn from Him, serve Him, teach to one another what they knew from Him, and so forth.
These great ennobled personalities of Islam, would remain upon a platform, just adjacent to what was then the Messenger of Allah
Salla Allahu ta'ala 'alayhi wa Sallam's Mosque, also known today as Majid-e-Nabwi, and were known as the 'ashaab-e-suffah'. This was due to the fact that the garment they would wear, or because of the platform that they stayed on was from what the word 'suff' or 'saff' means. Thus the one who wears such a garment literally means 'a sufi', thus deriving thier name from the material clothing they wore, or the place where they stayed.
There were many 'ashaab-e-Suffah', the names of some which are Hadart Abu zar Ghifari, Hadrat Abu Hurayrah, Hadrat 'Abdullah ibn-e-Mas'ud, and Hadrat 'Abdullah ibne 'Umar Radi Allahu anhum ajma'in.
There duty was to learn Islam, from the Beloved Prophet of Allah
Salla Allahu ta'ala 'alayhi wa Sallam, thus establishing the first Islamic School from which education was given. They were so poor that they did not feed regularly, and the Messenger of Allah
Salla Allahu ta'ala 'alayhi wa Sallam, would say to those people who had the food for two people to share it with the 'ashaab-e-Suffah'.
These were the first Sufis of Islam who led a non-materialistic life, and were solely devoted to the command of the Messenger of Allah
Salla Allahu ta'ala 'alayhi wa Sallam. May Allah the Almighty give us all the opportunity to follow in their fottsteps, and may he make us a student of that school, in the ancient sense.
Wallahu A'lamu Biththawaab
M. Waseem Ashrafi