According to Parris, what is Hale doing when he is with the prisoners? Why does he want them to do it?

Parris says that Hale has returned to bring Rebecca to God; he wants the prisoners to confess. He wants them to confess in order to save their lives.

Parris, prayerfully holding up his hands: Excellency, hear me. It is a providence. Reverend Hale has returned to bring Rebecca Nurse to God.

Danforth, surprised: He bids her confess?

Parris, sitting: Hear me. Rebecca have not given me a word this three month since she came. Now she sits with him, and her sister and Martha Corey and two or three others, and he pleads with them, confess their crimes and save their lives.