Based on the situation with Judas that Peter just recounted, he recalls two Psalms of David that relate to the incident. The quote ends at the end of this verse.
These two phrases mean basically the same thing. The second emphasizes the meaning of the first by repeating the same idea with different words. (See: [[rc://en/ta/man/translate/figs-parallelism]])
Possible meanings are 1) that the word "field" refers to the field where Judas died or 2) that the word "field" refers to Judas's dwelling place and is a metaphor for his family line. (See: [[rc://en/ta/man/translate/figs-metaphor]])