Mustadrak al-Hakim — Hadith 4338

It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the people of the Suffah were seventy (70) men, and they did not even have cloaks to wrap themselves in.
This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), but they did not record it! Imam al-Hakim says: I reflected on these narrations reported about the people of the Suffah, and I found them to be among the most excellent of the Companions in piety, in reliance upon Allah, and in constant devotion to serving the Messenger of Allah (peace and blessings be upon him). Allah Almighty chose for them the same humility, poverty, single-minded devotion to the worship of Allah, and leaving of the world to its people that He had chosen for His Prophet (peace and blessings be upon him). They are the group to whom the Sufis have traced their affiliation century after century. So whoever follows their way, their patience in leaving the world, their contentment with poverty, and their refraining from asking others, is in every age a follower of the people of the Suffah and one who relies upon his Creator.