The Messenger of Allah ﷺ said, "When a slave fulfills the right of Allah and the right of his masters, he receives two rewards."
قال رسول الله ﷺ: إذا أدى العبد حق الله وحق مواليه، كان له أجران.
Muslim reported it in the Book of Oaths and Vows (1666:45), via Abu Muawiya, from Amash, from Abu Salih, from Abu Hurairah, who mentioned it. Abu Hurairah said, "I related it to Kaab, and Kaab said, 'No reckoning applies to him, nor to any believer of little means.'"