The Lord sent a prophet - The Jews say that this was Phinehas; but it is more likely that it was some prophet or teacher raised up by the Lord to warn and instruct them. Such were his witnesses, and they were raised up from time to time to declare the counsel of God to his rebellious people.
A prophet - His name is not given. (Compare Judges 2:1-3. The reference to Exodus 20:2 is plain, and supposes the people to whom the prophet addresses these words to be familiar with the facts recorded in that text.