The greater part of the ceremonies was transferred to the morning hours of Holy Saturday. This change, however, did not produce a new liturgical creation adapted to the new order of things. The old baptismal ceremonies were left untouched and have now, apparently, no other reason for preservation than their antiquity. The gap left in the liturgical services after the solemnities of the night had been transferred to the morning of Holy Saturday was filled in France, Germany, and in some other countries by a twofold new ceremony, which, however, was never adopted in Rome.
First, there was the commemoration of the Resurrection of Christ. At midnight, before Matins, the clergy in silence entered the dark church and removed the cross from the sepulchre to the high altar. Then the candles were lit, the doors opened, and a solemn procession was held with the cross through the church, the cloister, or cemetery. Whilst the procession moved from the altar to the door, the beautiful old antiphon, "Cum Rex gloriae", was sung, the first part softly (humili ac depressâ voce), to symbolize the sadness of the souls in limbo; from Advenisti desiderabilis the singers raised their voices in jubilation whilst the acolytes rang small bells which they carried. The full text of this antiphon, which has disappeared from the liturgy, follows:
Cum rex gloriae Christus infernum debellaturus intraret, et chorus angelicus ante faciem ejus protas principum tolli praeciperet, sanctorum populus, qui tenebatur in morte captivus, voce lacrimabili clamabat dicens: Advenisti desiderabilis, quem expectabamus in tenebris, ut educered hac nocte vinculatos de claustris. Te nostra vocabant suspiria, te large requirebant lamenta, tu factus est spes desperatis, magna consolatio in tormentis. Alleluja.
When the procession returned, in many churches the "Attollite portas" (Ps. xxiii) was sung at the door, in order to symbolize the victorious entry of Christ into limbo and hell. After the procession Matins were sung. In later centuries the Blessed Sacrament took the place of the cross in the procession. This ceremony is, with the approval of the Holy See, still held in Germany on the eve of Easter with simpler ceremonies, in the form of a popular devotion.
(Interestingly, in the Midnight Paschal liturgy as observed by certain Churches of the Byzantine Rite, the "Atollite portas" is also sung in dialogue form in front of the closed church doors. -- Pascal)