Our Lord Jesus Christ endured the Passion for our salvation, Saint Faustina was instructed that we should venerate the hour of His Death with the Three o'clock prayer.
Explained further in Dairy Entry 1320
"At Three O'clock, Implore My Mercy, especially for sinners; and, if only for a brief moment, immerse yourself in My Passion, particularly in My abandonment at the moment of agony. This is the hour of Great Mercy for the whole world. I will allow you to enter into My mortal sorrow. In the hour, I will refuse nothing to the soul that makes a request of Me in virtue of My Passion..."
THE 3 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, Jesus I Trust in You. (3x)
