"You will not let your Holy One see corruption"
Christ's death was a real death in that it put an end to his earthly human existence. But because of the union his body retained with the person of the Son, his was not a mortal corpse like others, for "divine power preserved Christ's body from corruption." Both of these statements can be said of Christ: "He was cut off out of the land of the living", and "My flesh will dwell in hope. For you will not abandon my soul to Hades, nor let your Holy One see corruption." Jesus' Resurrection "on the third day" was the proof of this, for bodily decay was held to begin on the fourth day after death.
Source: Catechism of the Catholic Church (Vatican.va)