Then was fulfilled what had been spoken by the prophet Jeremiah translates the same words used in 2.17; it is the last in the series of quotation formulas found in the Gospel (see 1.22). One way to express it here is “When this happened it made come true what the prophet Jeremiah had said would happen. He said….” The text is composite, and in this regard the New Jerusalem Bible footnote is instructive:

Actually this is a free quotation from Z[echariah] 11.12-13 combined with the idea of the purchase of a field, an idea suggested by J[eremiah] 32.6-15. This, plus the fact that Jeremiah speaks of potters (18.2f) who lived in the Hakeldama District (19.1f), explains how the whole text could by approximation be attributed to Jeremiah.

They took represents a form in Greek which may also be translated “I took” (New English Bible footnote), the meaning it has in the Septuagint of Zechariah 11.13. Except for the alternative wording of New English Bible, the third person plural form they took is preferred by all translations.

The price of him on whom a price had been set by some of the sons of Israel is a laboriously literal rendering. Many others also retain a form similar to that of the Greek text, but New American Bible (“a price set by the Israelites”) and Die Bibel im heutigen Deutsch (“what he was worth to the Israelites”) effectively eliminate the unnecessary repetition. New International Version has “the price set on him by the people of Israel,” which is close to Good News Translation: “the amount the people of Israel had agreed to pay for him.” Of course, the text says some of the sons, so that “some of the people” or “some of those people who were Israelites” may be better.

Quoted with permission from Newman, Barclay M. and Stine, Philip C. A Handbook on the Gospel of Matthew. (UBS Handbook Series). New York: UBS, 1988. For this and other handbooks for translators see here .