'Master' in the Bible

“And I will hand over the Egyptians to a hard and cruel master,And a mighty king will rule over them,” declares the Lord God of hosts.

And the people will be like the priest, the servant like his master, the maid like her mistress, the buyer like the seller, the lender like the borrower, the creditor like the debtor [as God’s impartial judgment of sin comes on all].

So now, exchange pledges with my master the king of Assyria and I will give you two thousand horses, if you are able on your part to put riders on them.

But the Rabshakeh said, “Has my master sent me to speak these words only to your master and to you, and not to the men sitting on the wall, doomed to eat their own dung and drink their own urine with you?”

It may be that the Lord your God will hear the words of the Rabshakeh [the commander], whom his master the king of Assyria has sent to taunt and defy the living God, and will avenge the words which the Lord your God has heard. Therefore, offer a prayer for the remnant [of His people] that is left.’”

Isaiah said to them, “You shall say the following to your master: ‘This is what the Lord says, “Do not be afraid because of the words that you have heard, with which the servants of the king of Assyria have blasphemed Me.