Jesus
calls it “The Hour of Mercy” at three o'clock,
because it is the hour of His death.
"At three o'clock, implore My mercy, especially for sinners; and, only for a brief moment, submerge yourself in My Passion, particularly in My discouragement t at the moment of My agony. This is the great mercy hour for the whole world. I will allow you to come into My mortal sadness. In this hour, nothing will be denied to the soul that makes a request by the merits of My Passion... " (Diary, 1320)
“I remind you, My daughter, that any time you hear the clock at third, submerge yourself completely in My mercy, adoring and glorifying it; begs its omnipotence for the whole world, and particularly for poor sinners; because al that moment mercy was opened wide for every soul. In this hour you can obtain everything for yourself and for others; in this hour was established the grace for the whole world - mercy triumphed over justice." "My daughter, try to pray Stations of the Cross in this hour, once you allow your duties permit it; and if you can not pray the Stations of the Cross, at least comes into the chapel for a moment and adore, in the Blessed Sacrament, My Heart, which is full of mercy. And if you can not comes into the chapel submerge yourself in prayer wherever you are, only for a brief moment. I claim veneration for My mercy from every creature, but first you, because I have given you the most profound understanding of this mystery.” (Diary, 1572)
And Jesus said to me:
"I want you to know more deeply the love that burns in My Heart for souls, and you will understand this when you meditate My Passion. Invoke My mercy for sinners; I want their salvation. When you say this prayer, with a contrite heart and with faith for a sinner, I will give him the grace of conversion. This is the prayer:
"O Blood and Water, which gushed forth from the Heart of Jesus as a fount of Mercy for us, I trust in You.". (Diary 186, 187)
You expired, Jesus, but the source of life gushed forth for souls, and the ocean of mercy opened up for the whole world. O Fount of Life, unfathomable Divine Mercy, encompasses the whole world and pours out you over us. (Diary 1319)