The troparion is first sung during
Paschal Matins at the end of the procession around the church which takes place at the beginning of Matins. When all are gathered before the church's closed front door, the clergy and faithful take turns chanting the troparion, and then it is used as a refrain to a selection of verses from Psalms 67 and 117 (this is the Septuagint numbering; the KJV numbering is 68 and 118):
Let God arise, let His enemies be scattered; let those who hate Him flee from before His face (Ps. 68:1)
As smoke vanishes, so let them vanish; as wax melts before the fire (Ps. 68:2a)
So the sinners will perish before the face of God; but let the righteous be glad (Ps. 68:2b)
This is the day which the Lord hath made, let us rejoice and be glad in it. (Ps. 118:24)
In the remainder of the Vigil it is sung after each ode of the canon, at the end of the Paschal stichera at the Aposticha, thrice at the dismissal of Matins, and at the beginning and end of the Paschal Hours. It is chanted again with the same selection of Psalm verses at the beginning of the Divine Liturgy, at the Little Entrance, during and following Communion, and at the dismissal of the Liturgy. It is then chanted again with the refrains at the beginning of Vespers, and at the dismissal of Vespers. This same pattern persists throughout Bright Week.
After Thomas Sunday (the Sunday after Pascha), it is either sung or read thrice at the beginning of most services and private prayers in place of the usual invocation of the Holy Spirit, "O Heavenly King", and at the dismissals, during the 39-day paschal afterfeast; that is, up to and including the day before the Ascension of the Lord.