Saturday of Souls (or Soul Saturday) is a day set aside for the commemoration of the dead within the liturgical year of the Eastern Orthodox Church. Saturday is a traditional day of prayer for the dead, because Christ lay dead in the Tomb on Saturday. It's held on the Saturday before Pentecost because the occasion of the coming of the Holy Spirit not only consists of the economy of living humanity's salvation, but that the departed also participate in this salvation. Thus, we offer up petitions for the Holy Spirit's grace to be poured out on the departed.