Narrated Anas bin Malik:
that the Messenger of Allah (ﷺ) said: "How many are there with dishevelled hair, covered with dust, possessing two cloths, whom no one pays any mind to - if he swears by Allah then He shall fulfill it. Among them is Al-Bara bin Malik." (DE)
English reference (DE): Vol. 1, Book 46, Hadith 3854 (DE)
Arabic reference (DE): Book 49, Hadith 4227 (DE)