Hide the Fast, but Keep to a Refusal

In the first case we think there can be no doubt that it is better for our abstinence to be hidden than to be shown to those who ask, and in cases of this kind we also admit that a lie cannot be avoided. But in the second there is no need for us to tell a lie. First, because we can refuse what a brother offers in his service in such a way as to bind ourselves by no firm decision; and next, because once we have refused, we can keep to our opinion without changing it.