Institutes of the Christian Religion
Calvin's conclusion is that "If any persons have scruples about admitting this article into the Creed, it will soon be made plain how important it is to the sum of our redemption: if it is left out, much of the benefit of Christ’s death will be lost." Calvin strongly opposed the notion that Christ freed prisoners, as opposed to traveling to Hell as part of completing his sufferings (Institutes of the Christian Religion, Book 2, chapter 16, sections 8-10),