Asceticism of the Shelter People

We are informed by Abu Muhammad b. Hayyan that ‘Abd al-Rahman b. Muhammad b. Salm was informed by Hannad b. al-Sari that Abu Mu‘awiya narrated on the authority of Hisham that al-Hasan said:

The Messenger of God, upon whom be God's blessings and peace, called on the People of the Shelter. "How are you this morning?" he asked. They replied that they were fine. "Today you are fine." he said. "In the future, you'll each take one dish in the morning and another at night, and you will drape your homes in fabrics like the Ka‘ba."
     "Will we stay true to the faith, O Messenger of God, when all this comes to us?" they asked.
     "Yes," he said.
     "Then on that day we will be fine indeed. We will give alms, and pay for slaves to be emancipated!"
     "On the contrary," said God's Messenger, God's blessings and peace be upon him. "You are better off today, for on that day you'll all fall prey to envy and resentment, and be parted from each other."

Abu Mu‘awiya's narration is incompletely sourced, [lacking as it does an informer between al-Hasan (d. 50/670) and Hisham (b. 61/680),] but we are informed by ‘Abd Allah b. Muhammad that Abu Yahya al-Razi said that Hannad b. al-Sari was informed by Yunus b. Bukayr that Sinan b. Saysan al-Hanafi reported that al-Hasan said:

I constructed a shaded portico for indigent Muslims. Other Muslims began contributing whatever they could for their benefit, and God's Messenger, God's blessings and peace be upon him, used to visit them. "Peace be upon you, O People of the Shelter!" he would say. "And upon you be peace, O Messenger of God!" they would reply.
     "How are you this morning?" the Prophet asked. "We're fine, O Messenger of God!" they said.
      He said, "Today you are better off than that day when each of you will take one dish in the morning and another at night, and you will wear one garment in the morning and a different one that night, and you will drape your homes in fabrics like the Ka‘ba."
     "We will indeed be fine that day!" they said. "God be thanked for what He gives us."
     "On the contrary," said God's Messenger, God's blessings and peace be upon him. "You are better off today."

The Shelter had different numbers of people living there as conditions varied throughout the year. When Medina was visited by fewer strangers in need of hospitality, their numbers would disperse and dwindle. But as delegations increased, and more visitors showed up in town, some would go to the Shelter and swell the numbers of its people.
      Their fame was for their most distinguishing characteristic, namely, the total poverty they elected and accepted as their inheritance. Not one owned more than a single garment, nor ate but the simplest foods. This we know from hadith:

We are informed by Abu Bakr b. Malik that ‘Abd Allah, the son of Ahmad b. Hanbal, was told by his father that Waki‘ was informed by Fudayl b. Ghazwan that Abu Hazm reported that Abu Hurayra said: 

I saw seventy People of the Shelter making their prayers, each clad in single robes, some reaching no lower than their knees, and each of them clutched his robe as he bowed in prayer, for fear of exposing his privates.

From The Ornament of God's Friends by Abu Nu‘aym al-Isbahani