During the third apparition of the Angel of Peace to the 3 Shepherd Children (Lucia, Francisco and Jacinta) at Fatima in 1916, the angel appeared holding in his left hand a chalice and over it, in the air, was a host from which drops of blood fell into the chalice. With the Blessed Sacrament suspended in the air, the Angel of Peace prostrated himself on the ground and recited this prayer three times. After giving the host to Lucia and the contents of the chalice to Jacinta & Francisco, he prostrated himself again on the ground and again repeated with the children 3 times the following prayer.
Most Holy Trinity, Father, Son and Holy Spirit, I adore You profoundly, and I offer You the Most Precious Body, Blood, Soul and Divinity of Jesus Christ, present in all the tabernacles of the world, in reparation for the outrages, sacrileges and indifferences by which He is offended. And by the infinite merits of His Most Sacred Heart and through the Immaculate Heart of Mary, I beg the conversion of poor sinners. Amen.
The above prayer is also known as Prayer of Reparation to the Most Holy Trinity and can be used as an Act of Reparation.