Abu Musa Al-Ash'ari (May Allah be pleased with him) reported:
The Messenger of Allah (ﷺ) said, "A slave who worships his Rubb (Allah) well and discharges efficiently and faithfully the duties which are assigned to him by his master, will have a double reward."[Al-Bukhari]. (IT)
App reference (IT): Book 12, Hadith 80 (IT)
Arabic/English book reference (IT): Book 12, Hadith 1364 (IT)