Matthew 27:9-10 Then was fulfilled that which was spoken by Jeremy the prophet,
Zechariah 11:12-13 Zechariah wrote about 30 pieces of silver which were thrown into the house of the Lord.
These two passages are sometimes used by critics of the Bible to show a contradiction in reference to the prophet whose prophecy was fulfilled after Judas had brought back the 30 pieces of silver (which he had received as reward for his conspiracy against Jesus) to the priests and they then bought a piece of land with that money. The record about this event is found in Matthew 27:9-10; but a record about 30 pieces of silver which were cast into the house of the LORD is not found in the book of Jeremiah but rather in the book of the prophet Zechariah. How then can this apparent contradiction be solved?
First of all one should read the records carefully to see whether one of the records may contain a hint for a particular detail which could lead to a solution.
Then was fulfilled that which was spoken by Jeremy the prophet, saying, And they took the thirty pieces of silver, the price of him that was valued, whom they of the children of Israel did value;
And gave them for the potter's field, as the Lord appointed me.
In various Bibles with center references or other reference systems you can find a note pointing the reader to Jeremiah 32 and to Zechariah 11. Those are traditionally the sections of Scripture which are regarded as the source for what is said in Matthew 27:9-10, even if their wording doesn't really quite match what is recorded in Matthew 27. There is only one hint to the purchase of a field in the book of Jeremiah, and a reference to 30 pieces of silver in Zechariah which however do not have much to do with the record in Matthew about Judas. The passage in Zechariah could perhaps best be the source for the wording in the quotation in Matthew, but a closer look at the text shows quickly that something different is being talked about.
And I said unto them, If ye think good, give me my price; and if not, forbear. So they weighed for my price thirty pieces of silver.
And the LORD said unto me, Cast it unto the potter: a goodly price that I was prised at of them. And I took the thirty pieces of silver, and cast them to the potter in the house of the LORD.
The record in Zechariah deals with a completely different situation, and there is no connection to be seen that it really is a prophecy about Judas.
What is really the problem, and what is the cause for this apparent contradiction? When we read carefully, the contradiction is caused by the claim that the section from Zechariah actually is the source from which Matthew quotes even though Matthew himself speaks of Jeremy the prophet" as the source. If one leaves the record in Matthew untouched, then at least there is already no contradiction between Jeremiah or Zechariah.
There remains the question where in the book of Jeremiah can this quotation be found. The difficulty is solved when we notice what is said in the record in Matthew and what really has been written!
Then was fulfilled that which was spoken by Jeremy the prophet, saying, And they took the thirty pieces of silver ...
Matthew does not even say that this was written in the book of Jeremiah, he only mentions that Jeremiah SPOKE this. These words by the prophet Jeremiah had been preserved and were well known, but they were not necessarily written down in the book of Jeremiah..
This apparent contradiciton is solved when we read the text carefully and when we understand it exactly as it is written without reading our own ideas into the text.