Usair b. Jabir reported that when people from Yemen came to help (the Muslim army at the time of jihad) he asked them

Is there amongst you Uwais b. 'Amir? (He continued finding him out) until he met Uwais. He said: Are you Uwais b., Amir? He said: Yes. He said: Are you from the tribe of Qaran? He said: Yes. He (Hadrat) 'Umar (again) said: Did you suffer from leprosy and then you were cured from it but for the space of a dirham? He said: Yes. He ('Umar) said: Is your mother (living)? He said: Yes. He ('Umar) said: I heard Allah's Messenger (ﷺ) say: There would come to you Uwais b. Amir with the reinforcement from the people of Yemen. (He would be) from Qaran, (the branch) of Murid. He had been suffering from leprosy from which he was cured but for a spot of a dirham. His treatment with his mother would have been excellent. If he were to take an oath in the name of Allah, He would honour that. And if it is possible for you, then do ask him to beg forgiveness for you (from your Lord). So he (Uwais) begged forgiveness for him. Umar said: Where do you intend to go? He said: To Kufa. He ('Umar) said: Let me write a letter for you to its governor, whereupon he (Uwais) said: I love to live amongst the poor people. When it was the next year, a person from among the elite (of Kufa) performed Hajj and he met Umar. He asked him about Uwais. He said: I left him in a state with meagre means of sustenance. (Thereupon) Umar said: I heard Allah's Messenger (ﷺ) as saying: There would come to you Uwais b. 'Amir, of Qaran, a branch (of the tribe) of Murid, along with the reinforcement of the people of Yemen. He had been suffering from leprosy which would have been cured but for the space of a dirham. His treatment with his mother would have been very kind. If he would take an oath in the name of Allah (for something) He would honour it. Ask him to beg forgiveness for you (from Allah) in case it is possible for you. So he came to Uwais and said.: Beg forgiveness (from Allah) for me. He (Uwais) said: You have just come from a sacred journey (Hajj) ; you, therefore, ask forgiveness for me. He (the person who had performed Hajj) said: Ask forgiveness for me (from Allah). He (Uwais again) said: You have just come from the sacred journey, so you ask forgiveness for me. (Uwais further) said: Did you meet Umar? He said: Yes. He (Uwais) then begged forgiveness for him (from Allah). So the people came to know about (the status of religious piety) of Uwais. He went away (from that place). Usair said: His clothing consisted of a mantle, and whosoever saw him said: From where did Uwais get this mantle?