Sahih Adab al-Mufrad

Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates from the Prophet (peace and blessings of Allah be upon him) that he said: "None of you should say, 'my slave man' or 'my slave woman,' and a slave should not say, 'my lord' or 'my lady.' The master should say, 'my young man' and 'my young woman,' and the slave should say, 'my master' and 'my mistress (my master and my mistress).' All of you are slaves, and the Lord is Allah, the Mighty and Majestic."