'Certain' in the Bible

that Hadad escaped to Egypt, he and some Edomites from his father’s servants with him, while Hadad was [still] a little boy.

Now a certain man of the sons of the prophets said to another by the word of the Lord, “Please strike me.” But the man refused to strike him.

But one man drew a bow at random and struck the king of Israel in a joint of the armor. So he said to the driver of his chariot, “Turn around and take me out of the fight, because I have been seriously wounded.”