Gregory the Great — on 1Chr 11:18 (Register of Epistles, Book 9, Epistle 122)

“I must tell you that I have been led to praise God the more for your work by what I have learnt from the report of my most beloved son Probinus the presbyter; namely that, your Excellency having issued a certain ordinance against the perfidy of the Jews, those to whom it related attempted to bend the rectitude of your mind by offering a sum of money; which your Excellency scorned, and, seeking to satisfy the judgment of Almighty God, preferred innocence to gold. With regard to this what was done by King David recurs to my mind, who, when the longed for water from the cistern of Bethlehem, which was wedged in by the enemy, had been brought him by obedient soldiers, said, God forbid that I should drink the blood of righteous men. And, because he poured it out and would not drink it, it is written, He offered it a libation to the Lord. If, then, water was scorned by the armed king, and turned into a sacrifice to God, we may estimate what manner of sacrifice to Almighty God has been offered by the king who for His love has scorned to receive, not water, but gold. Wherefore, most excellent son, I will confidently say that thou hast offered as a libation to the Lord the gold which thou wouldest not have in opposition to Him.”