'Master's' in the Bible

Then the king called Saul’s servant Ziba and said to him, “All that belonged to Saul and to all his house I have given to your master’s grandson.

You and your sons and your servants shall cultivate the land for him, and you shall bring in the produce so that your master’s grandson may have food; nevertheless Mephibosheth your master’s grandson shall eat at my table regularly.” Now Ziba had fifteen sons and twenty servants.

I also gave you your master’s house and your master’s wives into your care, and I gave you the house of Israel and Judah; and if that had been too little, I would have added to you many more things like these!

Then the king said, “And where is your master’s son?” And Ziba said to the king, “Behold, he is staying in Jerusalem, for he said, ‘Today the house of Israel will restore the kingdom of my father to me.’”