Transfiguration

God,
in the glorious transfiguration of your only Son
you confirmed the mysteries of the faith
by the testimony of Moses and Elijah.[1]
In the voice that came from the bright cloud
you wondrously foreshowed our adoption as your children.
Mercifully make us heirs of glory with Christ,
and bring us at last to share that same glory with him;
through your Son, Jesus Christ our Lord,
who lives and reigns with you and the Holy Spirit,
one God, now and forever.

Source: 15th Century, Historic Collect for Transfiguration

[1] Literally, “by the testimony of the fathers.”