The Messenger of Allah ﷺ said, "None of you should say, 'Give your lord a drink, feed your lord, help your lord perform his wudu.' And none of you should say 'my lord,' but rather 'my master and my patron.' And none of you should say 'my slave' or 'my slave girl,' but rather 'my young man, my young woman, and my boy.'"
وقال رسول الله ﷺ لا يقل أحدكم اسق ربك أطعم ربك وضئ ربك ولا يقل أحدكم ربي وليقل سيدي ومولاي ولا يقل أحدكم عبدي وأمتي وليقل فتاي فتاتي وغلامي
This is also sahih, and it is in the Sahifah Mufradah, number 84. Bukhari related it [3:150 print / 5:128-131 Fath] through the route of the Sahifah, and Muslim also related it through its route [7:47 print / 2:197 Bulaq]. The word "my boy" - which we added - was dropped from H and M, and it is established in K, in Jami al-Masanid, and in the two narrations of the Sahihayn and the Sahifah Mufradah.