Psalm 5:11: "But let all who take refuge in you rejoice; let them ever sing for joy, and spread your protection over them, that those who love your name may exult in you."
Philippians 4:4: "Rejoice in the Lord always; again I will say, Rejoice."
Psalm 8:3 (with verse 4 for more context): "3 When I look at your heavens, the work of your fingers, the moon and the stars, which you have set in place, 4 what is man that you are mindful of him, and the son of man that you care for him?"
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The text is public domain:
1 Joyful, joyful we adore Thee,God of glory, Lord of love!Hearts unfold like flow'rs before Thee,Praising Thee, their sun above.Melt the clouds of sin and sadness,Drive the gloom of doubt away.Giver of immortal gladness,Fill us with the light of day.2 All Thy works with joy surround Thee,Earth and heav'n reflect Thy rays,Stars and angels sing around Thee,Center of unbroken praise.Field and forest, vale and mountain,Flow'ry meadow, flashing sea,Chanting bird, and flowing fountainCall us to rejoice in Thee.3 Thou art giving and forgiving,Ever blessing, ever blest,Well-spring of the joy of living,Ocean-depth of happy rest!Father, Son, and Holy SpiritFountainhead of love divine:Joyful, we Thy heav'n inherit!Joyful, we by grace are Thine!
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The "joy" and the call to "rejoice" from Psalm 5:11 and Philippians 4:4 appear throughout the hymn. Psalm 8:3 seems to be the basis for the second verse, although there's a stronger resemblance to parts of Psalm 148.
This is a minor point, but "vale and mountain" in the second verse is a merism.
