From Fish Eaters:
It was to the Limbo of the Fathers that Christ descended, a place of the dead that was emptied through His Passion, Resurrection and Ascension, and no longer exists. By this "Harrowing of Hell," as His Descent is sometimes called, the doors to Heaven were swung open so that those who die in a state of grace may enter in, alleluia! Adam, Eve, Noe, Abraham, Moses, the good thief on the cross -- all the righteous were illuminated by the Presence of Christ in the place of death, making Sheol itself a paradise. They remained there with Him until His Bodily Resurrection when the the "bars of Hell" were broken down and they were later able to enter into Heaven itself with His glorious Ascension.
Today a great silence reigns on earth, a great silence and a great stillness. A great silence because the King is asleep. The earth trembled and is still because God has fallen asleep in the flesh and he has raised up all who have slept ever since the world began....He has gone to search for Adam, our first father, as for a lost sheep. Greatly desiring to visit those who live in darkness and in the shadow of death, he has gone to free from sorrow Adam in his bonds and Eve, captive with him -- He who is both their God and the son of Eve.. "I am your God, who for your sake have become your son....I order you, O sleeper, to awake. I did not create you to be a prisoner in hell. Rise from the dead, for I am the life of the dead." [Ancient Homily for Holy Saturday: PG 43, 440A, 452C; LH, Holy Saturday, OR]Because of this great silence, today there will be no Mass (until the Vigil Mass tonight, which technically is Easter); instead, there is a solemn service. Today is traditionally a day of abstinence in addition to being a day of fasting, until the Vigil Mass, when the Lenten Fast ends. Though this fasting requirement was abolished in the new Code of Canon Law, traditional Catholics follow the traditional practice. In some churches today, priests will bless Easter baskets containing the foods eaten tomorrow (in other places, the baskets will be blessed after the liturgy tomorrow). Baskets bearing Easter bread, Easter eggs, meats, butter, horseradish, and salt are brought to church, blessed, and taken home to await the great feast tomorrow.