The Prophet ﷺ said, "None of you should say, 'Feed your lord, perform ablution for your lord, give your lord to drink.' Rather, let him say, 'My master, my patron.' And none of you should say, 'My slave, my slave-girl.' Rather, let him say, 'My young man, my young woman, my boy.'"
عن النبي ﷺ أنه قال: لا يقل أحدكم: أطعم ربك، وضي ربك، اسق ربك، وليقل: سيدي مولاي، ولا يقل أحدكم: عبدي أمتي، وليقل: فتاي وفتاتي وغلامي.
Bukhari narrated it in the Book of Emancipation (2552), and Muslim in the Book of Manners (2249:15), both through Abdul-Razzaq, who said, Mamar informed us, from Hammam bin Munabbih, from Abu Hurairah, and he mentioned it. The wording is Bukhari's.