Doeg was an Edomite and a servant of King Saul. He tracked the movements of the fleeing David and reported them to King Saul.
1 Samuel 21:7David said to Ahimelech, “Isn’t there here under your hand spear or sword? For I have neither brought my sword nor my weapons with me, because the king’s business required haste.”
1 Samuel 22:9He inquired of Yahweh for him, gave him food, and gave him the sword of Goliath the Philistine.”1 Samuel 22:10Then the king sent to call Ahimelech the priest, the son of Ahitub, and all his father’s house, the priests who were in Nob; and they all came to the king.1 Samuel 22:11Saul said, “Hear now, you son of Ahitub.” He answered, “Here I am, my lord.”1 Samuel 22:12Saul said to him, “Why have you conspired against me, you and the son of Jesse, in that you have given him bread, and a sword, and have inquired of God for him, that he should rise against me, to lie in wait, as it is today?”1 Samuel 22:13Then Ahimelech answered the king, and said, “Who among all your servants is so faithful as David, who is the king’s son-in-law, captain of your body guard, and honored in your house?1 Samuel 22:14Have I today begun to inquire of God for him? Be it far from me! Don’t let the king impute anything to his servant, nor to all the house of my father; for your servant knows nothing of all this, less or more.”1 Samuel 22:15The king said, “You shall surely die, Ahimelech, you, and all your father’s house.”1 Samuel 22:16The king said to the guard who stood about him, “Turn, and kill the priests of Yahweh; because their hand also is with David), and because they knew that he fled, and didn’t disclose it to me.” But the servants of the king wouldn’t put out their hand to fall on the priests of Yahweh.1 Samuel 22:17The king said to Doeg), “Turn and attack the priests!” Doeg the Edomite turned, and he attacked the priests, and he killed on that day eighty-five people who wore a linen ephod.1 Samuel 22:18He struck Nob, the city of the priests, with the edge of the sword, both men and women, children and nursing babies, and cattle and donkeys and sheep, with the edge of the sword.