St. Bridget declares in her Revelations, and her testimony is quoted by Benedict XIII., that she heard a voice from the depths of the Purgatorial flames pronouncing these words:
"May those be blessed, may those be rewarded, who relieve us in these pains ! "
And on another occasion :
"Lord God, show Thy Almighty power in recompensing a hundred-fold those who assist us by their suffrages, and make the rays of the divine light to shine upon us."
In another vision the saint heard the voice of an angel saying :
"Blessed be upon earth those who, by their prayers and good works, come to the assistance of the poor suffering souls ! "
~ Excerpt from Purgatory: Illustrated by the Lives and Legends of the Saints ~
by Fr. F.X. Shouppe, S.J.