'Master' in the Bible

Jonathan called out to the servant, "Hurry! Go faster! Don't delay!" Jonathan's servant retrieved the arrow and came back to his master.

David said to him, "To whom do you belong, and where are you from?" The young man said, "I am an Egyptian, the servant of an Amalekite man. My master abandoned me when I was ill for three days.

David said to him, "Can you take us down to this raiding party?" He said, "Swear to me by God that you will not kill me or hand me over to my master, and I will take you down to this raiding party."