'Master's' in the Bible

When Jehu rejoined his master's servants, they asked him, "Is everything all right? Why did this madman visit you?" He replied, "Ah, it's not important. You know what kind of man he is and the kinds of things he says."

pick the best and most capable of your master's sons, place him on his father's throne, and defend your master's dynasty."

He wrote them a second letter, saying, "If you are really on my side and are willing to obey me, then take the heads of your master's sons and come to me in Jezreel at this time tomorrow." Now the king had seventy sons, and the prominent men of the city were raising them.

Certainly you will not refuse one of my master's minor officials and trust in Egypt for chariots and horsemen.