Those who have purchased Property belonging to the Church, or received it as a Gift, are to restore it
And since it would be wrong in a provision intended to include all cases, to pass over those who have either procured any such property by right of purchase from the treasury, or have retained it when conveyed to them in the form of a gift; let all who have thus rashly indulged their insatiable thirst of gain be assured that, although by daring to make such purchases they have done all in their power to alienate our clemency from themselves, they shall nevertheless not fail of obtaining it, so far as is possible and consistent with propriety in each case. So much then is determined.
Source: Life of Constantine (New Advent)