Matthew 25:31: "'When the Son of Man comes in his glory, and all the angels with him, then he will sit on his glorious throne.'"
Revelation 22:20: "He who testifies to these things says, 'Surely I am coming soon.' Amen. Come, Lord Jesus!"
Daniel 7:13-14: "'I saw in the night visions, and behold, with the clouds of heaven there came on like a son of man, and he came to the Ancient of Days and was presented before him. And to him was given dominion and glory and a kingdom, that all peoples, nations, and languages should serve him; his dominion is an everlasting dominion, which shall not pass away, and his kingdom one that shall not be destroyed.'"
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The text is public domain:
The King shall come when morning dawns
And light triumphant breaks,
When beauty gilds the eastern hills
And life to joy awakes.
Not as of old a little child,
To bear and fight and die,
But crowned with glory like the sun
That lights the morning sky.
Oh, brighter than the rising morn
When Christ, victorious, rose
And left the lonesome place of death
Despite the rage of foes.
Oh, brighter than that glorious morn
Shall dawn upon our race
The day when Christ in splendor comes
And we shall see His face.
The King shall come when morning dawns
And light and beauty brings.
Hail, Christ the Lord! Your people pray:
Come quickly, King of kings!
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Aside from the resemblance between "But crowned with glory like the sun" and "'When the Son of Man comes in his glory'" (which isn't even that much of a resemblance), there don't seem to be many similarities between the hymn text and the Biblical passages cited. It seems like the hymn is just elaborating on what the Bible says.
