I remind you, My daughter, that as often as you hear the clock strike the third hour,
immerse yourself completely in My mercy, adoring and glorifying it;
invoke its omnipotence for the whole world, and particularly for poor sinners;
for at that moment mercy was opened wide for every soul.
In this hour you can obtain everything for yourself and for others for the asking;
it was the hour of grace for  the whole world-mercy triumphed over justice. 

THREE O'CLOCK PRAYER
You expired, O Jesus, but the source of life gushed forth for souls
and an ocean of mercy opened up for the whole world.
O Fount of Life, unfathomable Divine Mercy,
envelop the whole world and empty Yourself out upon us.
O Blood and Water, which gushed forth from the Heart of Jesus
as a fount of mercy for us, I trust in You.

The Three O’Clock Hour
Diary note 1572: 

My daughter, try your best to make the Stations of the Cross in this hour,
provided that your duties permit it;
and if you are not able to make the Stations of the Cross,
then at least step into the chapel for a moment and adore, in the Blessed Sacrament, My Heart, which is full of mercy; and should you be unable to step into the chapel,
immerse yourself in prayer there where you happen to be,
if only for a very brief instant.
I claim veneration for My mercy from every creature, but above all from you,
since it is to you that I have given the most profound understanding of this mystery.