"Suffa" is the name of the place where the Companions who devoted their material-spiritual beings and lives to the service of our beloved Prophet (pbuh). It was a place built behind the Mosque of the Prophet for the Companions who did not have a house, family and any material possessions. The Prophet (pbuh) himself took care of the education and instruction of the people of Suffa who lived in that modest place. He taught the principles and the truths that surrounded the world first to Ashab as-Suffa. The people of Suffa spent all of their time obtaining knowledge, meditating and worshipping. These mujahids, who were ready to sacrifice their lives for their holy cause, fought against the polytheists who attacked the Muslims with their swords when they could not answer the Quran with their words; most of them attained the lofty level of martyrdom. When there was a need for people for conveying the message of Islam and for jihad, the Prophet chose people from Ashab as-Suffa first.
Describing Ashab as-Suffa as students who devoted themselves in the way of Allah, Elmalılı Hamdi Yazır states the following in summary:
“Therefore, madrasahs (religious schools) are built next mosques in the Islamic world and the students studying there are expected to follow the way of Ashab as-Suffa: Obtaining knowledge, worshipping, bearing all kinds of hardships in the way of the religion, preserving their chastity, serving in order to spread the religion of Islam, making jihad when it is necessary…” 
Ashab as-Suffa, who never left the Prophet, who shared his troubles with his Companions, alone and who attained high ranks through his luminous talks, received a great lesson of self-sacrifice from him.
There is not a definite number of Ashab as-Suffa. Their number increased and decreased from time to time. Some of them got married with the permission of the Prophet; some of them died and some of them went to different places with the duty of conveying the message of Islam. However, it is known that their number changed between 100 and 400.
 Hak Dini Kur'ân Dili, 2: 9 40.