Mua'dh bin Hisham bin Aby معاذ بن هشام بن أبي عبد الله · General Behavior (Kitab Al-Adab)

The Prophet (ﷺ) said: None of you must say: "My slave" (abdi) and "My slave-woman" (amati), and a slave must not say: "My lord" (rabbi or rabbati). The master (of a slave) should say: "My young man" (fataya) and "My young woman" (fatati), and a slave should say "My master" (sayyidi) and "My mistress" (sayyidati), for you are all (Allah's slave and the Lord is Allah, Most High.

The Jews used to try to sneezes in the presence of the Prophet (ﷺ) hoping that he would say to them: "Allah have mercy on you!" but he would say: May Allah guide you and grant you well-being!