The Hebrew verb yapha means to shine, shine forth, or be resplendent. It occurs 8 times in the Old Testament and is used exclusively of God's glorious self-revelation — His radiant appearing in power and splendor. It describes the visible manifestation of God's glory breaking forth like light.
Yapha is a theophanic word — it appears in contexts where God manifests His presence in visible glory. In Deuteronomy 33:2, God "shone forth" from Mount Paran; in Psalm 50:2, from Zion God "shines forth" in perfect beauty; in Psalm 80:1, the psalmist pleads for God to "shine forth" in deliverance. The word captures the awe-inspiring, overwhelming brilliance of God's appearing and carries the prayer of the faithful that God would reveal His glory once again.