Bede : And David answered and said: Behold, one of the king's servants shall pass over and take it, etc. The Lord, responding through His teachers to the repentant Jews and those who have turned from the crime of persecution, said: Behold, the power of your kingdom rests with me; let the unity of the faithful pass into the unbelieving hearts of the proud, and let the spiritual weapons of the heavenly kingdom promised to you long ago be brought back swiftly. This was fulfilled in no small part in the times of the apostles, and remains to be fully completed in the times of Elijah, who preached and brought back the hearts of the fathers to the children. He says nothing about taking the cup of water, because the Lord does not teach that the shadow of the law should continue to be observed. The title of Psalm 53 remembers the betrayal of the Ziphites, which seems to refer more to an earlier betrayal, whereas there it is said according to the title: Is not David hidden among us? But here it is different: Behold, David is hidden in the hill of Achilah. — Commentary on Samuel