'Master's' in the Bible

And Elisha sat in his house, and the elders sat with him. And the king sent a man before him. Before the messenger came to him, he himself said to the elders, Do ye see how this son of a murderer has sent to take away my head? See, when the messenger comes; shut the door, and keep him off with the door: is not the sound of his master's feet behind him?

And now, when this letter comes to you, seeing your master's sons are with you, and there are with you chariots, and horses, and a fortified city, and armour,

look out the best and worthiest of your master's sons, and set him on his father's throne, and fight for your master's house.

And he wrote a letter the second time to them saying, If ye are mine, and will hearken to my voice, take the heads of the men your master's sons, and come to me to Jizreel to-morrow at this time. Now the king's sons, seventy persons, were with the great men of the city, who brought them up.

How then wilt thou turn away the face of one captain of the least of my master's servants? And thou reliest upon Egypt for chariots and for horsemen!