Charles Ellicott Commentary Nehemiah 5:12

"Then said they, We will restore them, and will require nothing of them; so will we do, even as thou sayest. Then I called the priests, and took an oath of them, that they would do according to this promise." — Nehemiah 5:12 (ASV)

We will restore. —The promise was given to restore the mortgaged property and to require no more interest. But Nehemiah required an oath to give legal validity to the procedure, and the priests’ presence gave it the highest religious sanction.