Sunan Ibn Majah
Hadith #4115
It was narrated from Mu’adh bin Jabal that the Messenger of Allah (ﷺ) said:“Shall I not tell you about the kings of Paradise?’ I said: ‘Yes.’ He said: ‘A weak and oppressed man who wears tattered clothes and is not paid any heed. If he swears (an oath) by Allah, Allah fulfills it.’”