Ibn 'Umar (May Allah be pleased with them) reported:
I heard the Messenger of Allah (ﷺ) saying, "When a slave is sincere to his master and worships Allah well, He will have a double reward."[Al-Bukhari and Muslim]. (TR)
App reference (TR): Book 12, Hadith 78 (TR)
Arabic/English book reference (TR): Book 12, Hadith 1362 (TR)