Pieces of silver is a term used to refer to coins or other forms of currency. It is derived from the Bible, where it is mentioned in the parable of the talents. In this parable, a master gives three of his servants different amounts of money, with one receiving five pieces of silver. The term is also used in other contexts, such as when referring to a payment or reward. In the crossword, the answer to the clue 'knives' (6 letters) is 'pieces' - a reference to the pieces of silver mentioned in the parable.