The Book of Common Prayer, Morning Collect for Saturdays
Almighty God, who after the creation of the world rested from all your works and sanctified a day of rest for all your creatures: Grant that we, putting away all earthly anxieties, may be duly prepared for the service of your sanctuary, and that our rest here upon earth may be a preparation for the eternal rest promised to your people in heaven; through Jesus Christ our Lord. Amen.
Evening Collect for Saturdays
O God, the source of eternal light: Shed forth your unending day upon us who watch for you, that our lips may praise you, our lives may bless you, and our worship on the morrow give you glory; through Jesus Christ our Lord. Amen.
I'm still less than adept at taking the right amount of rest, and that idea of coming to Sunday worship spiritually prepared gets away from me. But I'm learning.